The present invention relates to a wireless sensor network coverage enhancement algorithm based on gridding and an improved particle swarm optimization (PSO) algorithm. An improved PSO algorithm is provided based on the conventional PSO algorithm and wireless sensor network gridding, and is characterized in that nonlinear inertia factors are introduced on the basis of the conventional PSO algorithm. Compared with the conventional algorithms, the improved PSO algorithm has a better convergence ability and a better universal search ability, thereby greatly reducing the calculated amount of nodes, giving a more superior node deployment strategy, and raising a coverage rate. The wireless sensor network coverage enhancement algorithm provided by the present invention can be widely applied to various fields of wireless sensor networks, such as military, environmental monitoring and medical treatment and health.