将此bat放入Android Sdk的build-tools/{版本号}文件夹下 然后把jar拖到bat上即可转换到dex，原dx.bat逻辑和命令有问题，改了下方便转换，记得修改JAVA_HOME。

dx_jar2dex.bat

@echo off

setlocal

set prog=%~f0

set JAVA_HOME=C:\Users\see\Documents\android-studio\jre
set java_exe=%JAVA_HOME%\bin\java.exe

set jarfile=dx.jar
set "frameworkdir=%~dp0"

set "frameworkdir=%frameworkdir:~0,-1%"

if exist "%frameworkdir%\%jarfile%" goto JarFileOk
    set "frameworkdir=%~dp0lib"

if exist "%frameworkdir%\%jarfile%" goto JarFileOk
    set "frameworkdir=%~dp0..\framework"

:JarFileOk

set "jarpath=%frameworkdir%\%jarfile%"

set javaOpts=
set args=

set defaultXmx=-Xmx1024M
set defaultXss=-Xss1m

set params=

:firstArg
if [%1]==[] goto endArgs
set a=%~1

    if [%defaultXmx%]==[] goto notXmx
    if %a:~0,5% NEQ -JXmx goto notXmx
        set defaultXmx=
    :notXmx

    if [%defaultXss%]==[] goto notXss
    if %a:~0,5% NEQ -JXss goto notXss
        set defaultXss=
    :notXss

    if %a:~0,2% NEQ -J goto notJ
        set javaOpts=%javaOpts% -%a:~2%
        shift /1
        goto firstArg

    :notJ
    set params=%params% --dex --output=%~n1.dex %1
    shift /1
    goto firstArg

:endArgs

set javaOpts=%javaOpts% %defaultXmx% %defaultXss%
call "%java_exe%" %javaOpts% -classpath "%frameworkdir%" -jar "%jarpath%" %params%
pause