Bus rapid transit (BRT) is one of most effective methods to optimize urban traffic. Transit signal priority (TSP) is very important to increase the efficiency of BRT. TSP provides priority signals for public transport vehicles based on the advanced inspection and communication system. In this paper, TSP control system is designed with wireless sensor networks, which can support real-time information exchanging and bus positioning function through critical time synchronization. Taking into consideration that TSP maybe interfere other vehicles when giving the priority to public transport vehicles, this paper puts forward a fuzzy control algorithm which decides what kinds of traffic signals support based on the bus information. And this algorithm can reduce average vehicle delay at intersection, and realize the optimal control balance between bus priority and other vehicles.