The performance of CCTMXTiledMap is very low

I created a CCTMXTiledMap in my game and some other UIs and Labels. The FPS is 60fps with tile map invisible.
When show tile map, contains one layer with 1600 tiles, the FPS will drop down to 45 from 60.
When show tile map, contains 4 layers, the FPS will drop down to 33 from 60.

My phone is Lumia 520, vs2012 can’t do profile on it with unknown reason. What can I do to find the core reason of the FPS down problem? Whether it is caused by CCSpriteBatchNode or the tile map it self?