WSAN (wireless sensor and actor network) is the leading edge of the hot research field, which is developing rapidly in recent years. Routing Protocol plays a crucial role in WSAN. Most of current routing protocol can facilitate data interaction and collaborative execution between actors. Considering performance parameters e.g. delay, bandwidth, energy and reliability, a Distributed QoS Routing Protocol based on Ant Colony Optimization (DQRP_ACO) in WSAN has been proposed in this paper. The simulation results show that the DQRP_ACO can meet the requirments of WSAN under different application background, and improve the network performance.