一、在Assets\Editor目录下放个脚本

using UnityEngine;
using UnityEditor;
using System;
using System.IO;
using System.Collections.Generic;

/// <summary>
/// 命令行批处理工具类
/// </summary>
public class Batchmode {

    static List<string> levels = new List<string>();
    static string keystoreFile = @"D:\keystore.txt";

    public static void BuildAndroid() {
        
        //System.Environment.GetCommandLineArgs()//获取命令行参数
        if(!File.Exists(keystoreFile))
            throw new Exception("Not find keystore file");

        StreamReader sr = File.OpenText(keystoreFile);
        string password = sr.ReadToEnd().Trim();

        PlayerSettings.Android.keystorePass = password;
        PlayerSettings.Android.keyaliasPass = password;

        foreach ( EditorBuildSettingsScene scene in EditorBuildSettings.scenes ) {
            if ( !scene.enabled ) continue;
            levels.Add( scene.path );
        }
		EditorUserBuildSettings.SwitchActiveBuildTarget(BuildTarget.Android);
        string res = BuildPipeline.BuildPlayer( levels.ToArray(), "android.apk", BuildTarget.Android, BuildOptions.None );
        if (res.Length > 0)
            throw new Exception("BuildPlayer failure: " + res);
    }
}

二、写个批处理(路径改成自己的工程路径)

@echo off
@set unity="C:\Program Files\Unity\Editor\Unity.exe"
echo 正在生成APK文件...
%unity%  -batchmode -quit -nographics -executeMethod Batchmode.BuildAndroid  -logFile D:\Editor.log -projectPath "D:\China\2014-11-12_client_wushen_android" 
echo APK文件生成完毕!
pause