diff --git a/reinstall.sh b/reinstall.sh
index 008cd17..f1eb8e6 100644
--- a/reinstall.sh
+++ b/reinstall.sh
@@ -1358,50 +1358,55 @@ Continue?
         # 注意 windows server 2008 r2 serverdatacenter 不用改
         image_name=${image_name/windows server 2008 server/windows longhorn server}
 
-        iso_filetype='iso raw'
-        iso_tested=false
+        if [[ "$iso" = magnet:* ]]; then
+            : # 不测试磁力链接
+        else
+            iso_filetype='iso raw'
+            iso_tested=false
 
-        # 获取 massgrave.dev 直链
-        if grep -Eiq '\.massgrave\.dev/.*\.(iso|img)' <<<"$iso"; then
-            # 如果已经是 iso 直链则跳过下面的 iso 测试
-            if test_url_grace "$iso" "$iso_filetype"; then
-                iso_tested=true
+            # 获取 massgrave.dev 直链
+            if grep -Eiq '\.massgrave\.dev/.*\.(iso|img)' <<<"$iso"; then
+                # 如果已经是 iso 直链则跳过下面的 iso 测试
+                if test_url_grace "$iso" "$iso_filetype"; then
+                    iso_tested=true
+                else
+                    msg="Could not find direct link for $iso"
+                    if ! iso=$(grep -oE 'https?.*\.iso[^"]*' $tmp/img-test | sed 's/&amp;/\&/g' | grep .); then
+                        error_and_exit "$msg"
+                    fi
+                fi
+            fi
+
+            # 测试是否是 iso
+            if ! $iso_tested; then
+                test_url "$iso" "$iso_filetype"
+            fi
+
+            # 判断 iso 架构是否兼容
+            # https://gitlab.com/libosinfo/osinfo-db/-/tree/main/data/os/microsoft.com?ref_type=heads
+            # uupdump linux 下合成的标签是 ARM64，windows下合成的标签是 A64
+            if file -b "$tmp/img-test" | grep -Eq '_(A64|ARM64)'; then
+                iso_arch=arm64
             else
-                msg="Could not find direct link for $iso"
-                if ! iso=$(grep -oE 'https?.*\.iso[^"]*' $tmp/img-test | sed 's/&amp;/\&/g' | grep .); then
-                    error_and_exit "$msg"
+                iso_arch=x86_or_x64
+            fi
+
+            if ! {
+                { [ "$basearch" = x86_64 ] && [ "$iso_arch" = x86_or_x64 ]; } ||
+                    { [ "$basearch" = aarch64 ] && [ "$iso_arch" = arm64 ]; }
+            }; then
+                warn "
+The current machine is $basearch, but it seems the ISO is for $iso_arch. Continue?
+当前机器是 $basearch，但 ISO 似乎是 $iso_arch。继续安装?"
+                read -r -p '[y/N]: '
+                if ! [[ "$REPLY" = [Yy] ]]; then
+                    exit
                 fi
             fi
         fi
 
-        # 测试是否是 iso
-        if ! $iso_tested; then
-            test_url "$iso" "$iso_filetype"
-        fi
-
         [ -n "$boot_wim" ] && test_url "$boot_wim" 'wim'
 
-        # 判断 iso 架构是否兼容
-        # https://gitlab.com/libosinfo/osinfo-db/-/tree/main/data/os/microsoft.com?ref_type=heads
-        if file -b "$tmp/img-test" | grep -q '_A64'; then
-            iso_arch=arm64
-        else
-            iso_arch=x86_or_x64
-        fi
-
-        if ! {
-            { [ "$basearch" = x86_64 ] && [ "$iso_arch" = x86_or_x64 ]; } ||
-                { [ "$basearch" = aarch64 ] && [ "$iso_arch" = arm64 ]; }
-        }; then
-            warn "
-The current machine is $basearch, but it seems the ISO is for $iso_arch. Continue?
-当前机器是 $basearch，但 ISO 似乎是 $iso_arch。继续安装?"
-            read -r -p '[y/N]: '
-            if ! [[ "$REPLY" = [Yy] ]]; then
-                exit
-            fi
-        fi
-
         eval "${step}_iso='$iso'"
         eval "${step}_boot_wim='$boot_wim'"
         eval "${step}_image_name='$image_name'"
diff --git a/trans.sh b/trans.sh
index bd13ef6..c354a4f 100644
--- a/trans.sh
+++ b/trans.sh
@@ -84,12 +84,13 @@ wget() {
 }
 
 is_have_cmd() {
-    command -v "$1" >/dev/null
+    # command -v 包括脚本里面的方法
+    is_have_cmd_on_disk / "$1"
 }
 
 is_have_cmd_on_disk() {
-    os_dir=$1
-    cmd=$2
+    local os_dir=$1
+    local cmd=$2
 
     for bin_dir in /bin /sbin /usr/bin /usr/sbin; do
         if [ -f "$os_dir$bin_dir/$cmd" ]; then
@@ -127,6 +128,18 @@ retry() {
     done
 }
 
+get_url_type() {
+    if [[ "$1" = magnet:* ]]; then
+        echo bt
+    else
+        echo http
+    fi
+}
+
+is_magnet_link() {
+    [[ "$1" = magnet:* ]]
+}
+
 download() {
     url=$1
     path=$2
@@ -138,26 +151,17 @@ download() {
     # https://aria2.github.io/manual/en/html/aria2c.html#cmdoption-o
 
     # 构造 aria2 参数
-    # 没有指定文件名的情况
-    if [ -z "$path" ]; then
-        save=""
-    else
-        # 文件名是绝对路径
-        if [[ "$path" = '/*' ]]; then
-            save="-d / -o $path"
-        else
-            # 文件名是相对路径
-            save="-o $path"
-        fi
+    save=
+    # 文件夹
+    if [[ "$path" = '/*' ]]; then
+        save="$save -d /"
     fi
-
-    if ! is_have_cmd aria2c; then
-        apk add aria2
-    fi
-
-    # stdbuf 在 coreutils 包里面
-    if ! is_have_cmd stdbuf; then
-        apk add coreutils
+    # 文件名
+    if [ -n "$path" ]; then
+        case "$(get_url_type "$url")" in
+        http) save="$save -o $path" ;;
+        bt) save="$save -O 1=$path" ;;
+        esac
     fi
 
     # 阿里云源限速，而且检测 user-agent 禁止 axel/aria2 下载
@@ -175,13 +179,18 @@ download() {
     # fi
 
     # --user-agent=Wget/1.21.1 \
+    # --retry-wait 5
 
-    echo "$url"
-    retry 5 5 stdbuf -oL -eL aria2c -x4 \
-        --allow-overwrite=true \
-        --summary-interval=0 \
-        --max-tries 1 \
-        $save "$url"
+    # 检测大小时已经下载了种子
+    if [ "$(get_url_type "$url")" = bt ]; then
+        torrent="$(get_torrent_path_by_magnet $url)"
+        if ! [ -f "$torrent" ]; then
+            download_torrent_by_magnet "$url" "$torrent"
+        fi
+        url=$torrent
+    fi
+
+    aria2c $save "$url"
 }
 
 update_part() {
@@ -1037,6 +1046,10 @@ EOF
     done
 }
 
+newline_to_comma() {
+    tr '\n' ','
+}
+
 space_to_newline() {
     sed 's/ /\n/g'
 }
@@ -1990,6 +2003,96 @@ get_http_file_size() {
         tail -1 | awk '{print $2}' | grep .
 }
 
+get_url_hash() {
+    url=$1
+
+    echo "$url" | md5sum | awk '{print $1}'
+}
+
+aria2c() {
+    if ! is_have_cmd aria2c; then
+        apk add aria2
+    fi
+
+    # stdbuf 在 coreutils 包里面
+    if ! is_have_cmd stdbuf; then
+        apk add coreutils
+    fi
+
+    # 指定 bt 种子时没有链接，因此忽略错误
+    echo "$@" | grep -o '(http|https|magnet):[^ ]*' || true
+
+    # 下载 tracker
+    # 在 sub shell 里面无法保存变量，因此写入到文件
+    if echo "$@" | grep -Eq 'magnet:|\.torrent' && ! [ -f "/tmp/trackers" ]; then
+        # 独自一行下载，不然下载失败不会报错
+        # 里面有空行
+        # txt=$(wget -O- https://raw.githubusercontent.com/ngosang/trackerslist/master/trackers_best.txt | grep .)
+        # txt=$(wget -O- https://raw.githubusercontent.com/ngosang/trackerslist/master/trackers_all.txt | grep .)
+        txt=$(wget -O- https://cf.trackerslist.com/best.txt | grep .)
+        # sed 删除最后一个逗号
+        echo "$txt" | newline_to_comma | sed 's/,$//' >/tmp/trackers
+    fi
+
+    # --dht-entry-point=router.bittorrent.com:6881 \
+    # --dht-entry-point=dht.transmissionbt.com:6881 \
+    # --dht-entry-point=router.utorrent.com:6881 \
+    retry 5 5 stdbuf -oL -eL aria2c \
+        -x4 \
+        --seed-time=0 \
+        --allow-overwrite=true \
+        --summary-interval=0 \
+        --max-tries 1 \
+        --bt-tracker="$([ -f "/tmp/trackers" ] && cat /tmp/trackers)" \
+        "$@"
+}
+
+download_torrent_by_magnet() {
+    url=$1
+    dst=$2
+
+    url_hash=$(get_url_hash "$url")
+
+    mkdir -p /tmp/bt/$url_hash
+
+    # 不支持 -o bt.torrent 指定文件名
+    aria2c "$url" \
+        --bt-metadata-only=true \
+        --bt-save-metadata=true \
+        -d /tmp/bt/$url_hash
+
+    mv /tmp/bt/$url_hash/*.torrent "$dst"
+    rm -rf /tmp/bt/$url_hash
+}
+
+get_torrent_path_by_magnet() {
+    echo "/tmp/bt/$(get_url_hash "$1").torrent"
+}
+
+get_bt_file_size() {
+    url=$1
+
+    torrent="$(get_torrent_path_by_magnet $url)"
+    download_torrent_by_magnet "$url" "$torrent" >&2
+
+    # 列出第一个文件的大小
+    # idx|path/length
+    # ===+===========================================================================
+    #   1|./zh-cn_windows_11_consumer_editions_version_24h2_updated_jan_2025_x64_dvd_7a8e5a29.iso
+    #    |6.1GiB (6,557,558,784)
+
+    aria2c --show-files=true "$torrent" |
+        grep -F -A1 '  1|./' | tail -1 | grep -o '(.*)' | sed -E 's/[(),]//g' | grep .
+}
+
+get_link_file_size() {
+    if is_magnet_link "$1" >&2; then
+        get_bt_file_size "$1"
+    else
+        get_http_file_size "$1"
+    fi
+}
+
 pipe_extract() {
     # alpine busybox 自带 gzip，但官方版也许性能更好
     case "$img_type_warp" in
@@ -2073,7 +2176,7 @@ create_part() {
     # xda*1 星号用于 nvme0n1p1 的字母 p
     # shellcheck disable=SC2154
     if [ "$distro" = windows ]; then
-        if ! size_bytes=$(get_http_file_size "$iso"); then
+        if ! size_bytes=$(get_link_file_size "$iso"); then
             # 默认值，最大的iso 23h2 假设 7g
             size_bytes=$((7 * 1024 * 1024 * 1024))
         fi