In wireless multimedia sensor networks(WMSNs),unreasonable deployment of nods may cause many blind areas, which affects the service quality of networks greatly.To improve network coverage,a particle swarm optimization(PSO) algorithm based coverage enhancing algorithm(PSOCE) is proposed.Based on directional sensing model,PSOCE used PSO to search rational locations and directions for all sensor nodes to optimize the network coverage.Simulation showed that PSOCE could improve coverage quality of WMSNs efficiently,and the coverage rate was increased by 6%～12%.