This paper introduces the ant colony algorithm to the path planning of mobile robots, and explores the optimal path solution. The definition of path planning was studied firstly. Then modelling method of path planning was discussed. Also, current research status of three-dimensional path planning at home and abroad he existing problems of 3D path planning was analyzed. These basic theoretical knowledge have laid the foundation for the research work of this paper, and we then modelled the three-dimensional terrain environment, and used MATLAB software for simulation experiments to implement the ant colony algorithm to plan the robot’s three-dimensional terrain path, and finally performed fuzzy reinforcement learning method based on ant colony algorithm to find the optimal path for the mobile robot.