Abstract: Based on silicon micromachining technology, a novel deformable mirror with 30mm×30mm effective reflecting surface and 49 actuators is designed and fabricated. It is composed of a silicon membrane, at the back of which is attached by a 7×7 pillars array. The pillars and bonding part are fabricated through two etching steps with different depth. In terms of optimization, a strip pattern is designed specially for the convex corner compensation during the etching process, and the anodic bonding process is performed under 0.2MPa atmospheric pressures.