Aiming at the path planning of unmanned underwater vehicle(UUV)in unknown underwater complex environment，an RRT-DWA fusion algorithm was designed. The algorithm is based on two-layers planning design of rapid expansion random tree(RRT)and dynamic window(DWA). The first layer uses the RRT algorithm to quickly plan the global path. Based on this and considering the underactuation and non-linearity of the UUV model，the second layer loads the global path，and the DWA algorithm is used to complete the local path planning to ensure the safety of the UUV path under the constraints. The fusion parameters of the inner and outer frames are corrected by the fusion parameters μ，which effectively makes up for the shortcomings of the global path algorithm that cannot avoid dynamic obstacles and improves the low efficiency of the local path algorithm. Finally，the superiority of the RRT-DWA fusion algorithm compared with the RRT global algorithm and the DWA local algorithm is verified through comparative simulation.
