Yo!
I want to make two modules with other clock whose ratio is a power of two.
If i create slave clock by dividing master clock, do I need to solve metastability problem between two clock domain?
The phase of your generated clock will not be the same as master clock, because of clock divider timing paths (wires and logic inside it). So you have to options: synchronize paths from clk1 to clk2, and from clk2 to clk1, or you may leave them asynchronous and use CDC techniques.