![enter image description here][1] [1]: /editor/20161207/5847d257c4f9f.png

@dillon Thank you for your reply. Currently I have 4 layers, two inner layers are power plane and ground plane, respectively, and the top and bottom layers are signal layers. I only want the auto router to route on the top and bottom layers. But there is no option to designate it. I tried selecting the "TOP Only", but the inner layers were still routed. Do you have any ideas to solve this problem?

In This case, you just need to use 2 layer PCBs and skip the Power layer, after router, then add inner1 innner2 for power layer.

@dillon Thank you for your reply. I'll try it.