Abstract: This paper presents comprehensive performance index of multi-warship deployment for air defense, after analyzing various factors of incoming target and warship, which would affect the effectiveness of interception. This paper provides the formulation of the multiwarship cooperative deployment problem, and optimizes the cooperative deployment optimization problem of multiwarship by using the symbiosis organisms search (SOS) algorithm. The SOS algorithm optimizes the cooperative deployment optimization problem by simulating the mutualism phase, commensalism phase, and parasitism phase. Comparing to particle swarm optimization (PSO), SOS can obtain better solution with higher convergence rate. Numerical simulation results are provided to support the method in rationality. Compared with the PSO algorithm, the SOS algorithm performs better in this problem.