Moving object is very difficult to be associated with the time and space elements, and also difficult to solve the association. To solve the problems, a algorithm is proposed which take optimal path set’s data association algorithm, and the discrete particle swarm algorithm is brought to the solution. Firstly, the algorithm fuses the object’s appearance match similarity, time and space constraint by Bayesian network net, and then transforms the data association problem into the optimal path choice in the network. Secondly, the average sample pairs’ similarity between paths is set as evaluation function, and when its value is the maximum, the path is optimal. Finally, the emergence of target is discrete on time and space elements, so the discrete particle swarm algorithm is used to obtain the optimal path, and the target’s moving path is recorded by particle encode. The algorithm makes a tracking target simulation in the networks composed of five cameras. The results show that it can effectively solve the multiple target optimal path set, get the target’s movement in the network, realize the relay track, and have good robustness.