The creation is a folding cosmetic mirror . It contains a main mirror frame and two side mirror frames which set on the both sides of the main frame. The main and side frames are both connected by brackets.Each bracket has a guide groove which has a guide block on it. One side of the guide block protrudes from the guide block and connects the relative side mirror frame. By the moving of the guide block on the guide groove, the both side mirror frames will unfold from the relative main mirror frame. It can not only increase the size and depth of the mirror but also be carried easily. Besides, an auxiliary frame can be set on the main mirror frame to place on a tilt with the different location and position, and even put a extended frame inside the auxiliary frame and brackets to lift moderately of the cosmetic mirror and increase convenience of applying make up or combing.