Aiming at the shortcomings of the rapid exploration of random tree (RRT), the RRT algorithm is improved and optimized based on the research of mobile robot. According to the extension principle of the RRT, the simulation environment map is constructed, and the simulation experiments of the RRT optimization method based on probability P and based on bidirectional RRT are completed. A probabilistic P-bidirectional RRT optimization algorithm is proposed by combining 2 methods, and verified by simulation experiments. The simulation results show that the optimized RRT algorithm has good convergence and robustness in complex obstacle environments.