With the prediction of the rules of node reliability and residual energy, this paper presents a PRAS (Predicted Routing Algorithm with Stability) based on weighted Markov Chain. PRAS makes schemes for the routing of network QoS via researches on single optimal index and comprehensive optimal evaluation of nodes. Simulation results show that the route realized by PRAS routing is obviously better than usual probability in terms of the delivery ratio from average end-to-end delay.