The work aims to plan the optimal feasible path better. An improved three-dimensional real-time path planning algorithm based on three-level programming model (TLP) was proposed. Firstly, starting from the control performance of AGV, the threat level function was set by multiple constraints based on real scene, and a smoother optimal path was planned with TLP and improved RRT optimization algorithm. The objective function and the decision variables of TLP could ensure that AGV reached the target location accurately. Experimental results show that the proposed algorithm has better efficiency and effectiveness.