The direction angle sequence of the target is collected by the pyroelectric infrared sensing equipment, and the target tracking scheme without distance measuring is realized with the help of particle swarm optimization (PSO) algorithm. When the array layout is large, the collected length of direction angle sequence increases, the dimension of algorithm search space increases, and the tracking precision decreases. Through splitting sequence, the distributed particle swarm optimization algorithm (DPSO) integrated multi-node cooperative decision is used to realize the real-time target tracking in the large array of infrared detecting system. And the tracking accuracy meets the requirements. The experimental results show that the proposed method can effectively extend the application of the basic PSO algorithm in pyroelectric sensing.