Abstract: Aimed at the unknown global environment and the fact that the local optimal solution can be easily obtained from the common programming algorithm,an unknown three-dimensional environment path planning algorithm based on heuristic mapping method is proposed.Under the section planning strategy,the heuristic mapping method was used for acquiring the piecewise sub-targets,which overcame the defect that the conventional linear mapping method was difficult to determine the targets under certain circumstances.The planning task of the mobile agent was completed by combining A*algorithm in the three-dimensional environment.MATLAB was used for simulation.The result of the proposed algorithm is shorter in path length and less in running time compared with the result of the linear mapping method,showing that the proposed algorithm can better solve the path planning problem in unknown three-dimensional environment.