i dont want over work my Computer.
"Vsync", "Sys_Maxfps" Console command didn`t work in Editor Mode(Not in game Mode). is this bug or System Rule?
what should i do?

Using r_VSync=0 and then setting sys_MaxFPS=60 should work just fine. But VSync must be disabled before limitting FPS can work.

"This is by design" https://github.com/CRYTEK-CRYENGINE/CRYENGINE/issues/44

You could apply the proposed patch and use your own engine compiled copy.

How can i apply custom build?

You would need to dkownload the source code and modify then build it. There is a picture based tutorial in the collection of guides in community tutorials if this is something you wish to try.