Abstract: In unknown environment, the RRT route planning strategy lacks purpose-oriented feature and the solution deviates from the optimal one, to solve these problems, this paper presents a new method which combine the improved RRT algorithm and rolling plan window.The improved RRT algorithm introduce guide direction factor, which limit the extended range of nodes and strengthen the purpose of growth.Apply comparison method, to get better solution.Computer simulation results show that the new route planning algorithm can converges to a better solution in short time in unknown environment, and the new algorithm to solve path planning in unknown environment is feasible.