With the gradual complication of micro devices, the poor manufacturability of product becomes a bottleneck. In this paper, we discuss the optimal design method that involves the model restriction, model revising and cooperative design management. Firstly, the design rules checking for the original model is introduced, which constrains the 3D models into an appropriate form to satisfy the manufacturing requirements. Then, the informational description of micro device involves two levels. The device level modeling focuses on geometric information, while the process level modeling works at manufacturability. Based on the two level models, the model revising procedure is performed in cooperative design environment. Furthermore, a polysilicon electro-thermal actuator is used to illustrate the cooperative optimal design approach.