The separate situation of research has area coverage or target coverage in wireless sensor networks. Based on directional sensing model，the algorithm used the virtual potential field to make the sensor nodes shift positions and change directions automatically in monitoring area. Coverage on multiple targets is mainly in the quality of coverage and network service system. Coverage for multi-objective design is a multi-objective genetic algorithm to solve multi-objective optimization problem. Thinning algorithm can be found in the border region of the demand point for sparse areas which needs to make the search more uniform distribution of the solution. The operator introduces the compound of crossing two operators and a uniform mixing of the single point to make an analog binary search function be weak cross defects, and gives proof of the convergence of the algorithm by simulation to verify the effectiveness of the algorithm.