在project.properties里加上   proguard.config=proguard.cfg

proguard.cfg 配置如下：

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*

#忽略警告 也可以用-ignorewarnings
-dontwarn

#声明第三方jar包,不用管第三方jar包中的.so文件(如果有)
-libraryjars libs/baidumapapi.jar
-libraryjars libs/tencent_openapi.jar
-libraryjars libs/httpmime-4.1.3.jar
-libraryjars libs/weibo.sdk.android.sso.jar
-libraryjars libs/android-support-v4.jar

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService

-keepclasseswithmembernames class * {
native <methods>;
}

-keepclasseswithmembers class * {
public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
public void *(android.view.View);
}

-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
public static final android.os.Parcelable$Creator *;
}

#不混淆第三方jar包中的类
-keep class com.baidu.mapapi.** {*;}
-keep class com.tencent.tauth.** {*;}
-keep class org.apache.http.entity.mime.** {*;}
-keep class android.support.v4.** {*;}
-keep class android.net.http.** {*;}
-keep class com.weibo.sdk.android.** {*;}
-keep class com.sina.sso.** {*;}

说明一下，第三方jar包中如果有.so文件，不用去理会，引入的第三方jar文件不要混淆，否则可能会报异常