The network lifetime is an important measure of wireless sensor networks(WSNs) performance indicators. The emergence of coverage holes affects the network lifetime seriously. Therefore, a coverage holes detecting and healing algorithm based on the C-V model is proposed. Firstly, the sensing model based on Neyman-Pearson criterion is used to calculate the joint detection probability of each node location in the monitoring area. Then based on the improved C-V model, a novel coverage holes detection algorithm is proposed to obtain the number and the size of the holes effectively. Finally, an improved particle swam algorithm is used to heal the coverage holes. Simulation results show that the proposed algorithm can effectively maintain the coverage rate of the WSN and improve the life of the WSN.