In this paper, we proposed a novel probability convergence based particle swarm optimization algorithm for the multiple constrained QoS multicast routing. This algorithm is inspired from the probability convergence attributes. The main contents of this paper includes: (1) A novel particle sorting rule of swarm are designed. (2) A novel probability convergence mechanism is developed in the position updating phase. (3) A new anti-congestion tactic is introduced. Experiment result shows that the new algorithm has excellent performance in convergence speed and global astringency.