Aiming at the shortcomings of the traditional A* algorithm in UAV path planning, such as low efficiency, a large number of redundant path points, and many path transitions, an improved A* algorithm based on two-way mechanism is proposed. First, a bidirectional search mechanism is introduced, which takes the starting point of the opposite search as the end point, and then determines that the end point is located in the quadrant of the starting point for bidirectional search, so as to improve the search efficiency. Finally, the path smoothing strategy is introduced to smooth the initial path obtained by the bi directional search to reduce redundant path points and turning points. The traditional A* algorithm and the improved A* algorithm are compared through the MATLAB platform. The experimental results show that compared with the traditional A* algorithm, the improved A* algorithm proposed reduces the average path planning time by 61.61%, path points by 83.09%, and path turning points by 46.97%, which can effectively improve the working efficiency of UAVs and generate smooth paths.