Abstract: In order to solve the problem of deflection control of deflection algorithm, a deflection routing algorithm was proposed based on priority and load balancing in optical burst switching(OBS)networks. When conflict occurs, low priority bursts are segmented at first. Then, the contention part of bursts is deflected to free links. The algorithm selects many candidate routes on which the current maximum number of residual hops less than the maximum number of hops of the source-to-destination nodes. Finally, the algorithm chooses the best route that balances the assigned wavelengths of every links from candidate routes. This algorithm was analyzed in theory and simulated, and a series of data including the packet loss probability and the delay changing with network loads were obtained. Simulation results show that the delay of the proposed algorithm is located between the shortest path deflection routing algorithm and load-balancing deflection routing algorithm. It can efficiently reduce the packet loss probability of the entire network and protect the integrity of some high priority bursts. So the scheme can efficiently improve the performance of OBS networks.