Abstract: The four-way shuttle-based high-density storage system represents a new generation of stereoscopic warehouse solutions in high-density and complex environments. This paper aims to solve the problem that four-way shuttles tend to experience frequent turns and visit many invalid nodes during operation with defective areas, resulting in long task execution time and low algorithm search efficiency. By establishing a topological map of the storage environment, the search performance of different heuristic estimation functions in the four-way shuttle topological map is compared and analyzed. In scenarios with defective areas that may lead to significant deviations between heuristic estimates and actual path cost, a triangle-based heuristic method is introduced to improve the A* algorithm. A simulation platform for the four-way shuttle-based high-density storage system is constructed to verify the effectiveness of the proposed method. Simulation results show that the improved A* algorithm can effectively reduce the number of explored nodes and turning points, thereby improving the search efficiency.