Abstract: The pipeline design is one of the important contents of coal preparation plant design. At present, pipeline of coal preparation plant mainly depends on the manual design, which is difficult, time-consuming and difficult to guarantee the quality of pipeline layout. When A^* algorithm is applied to the automatic layout of three-dimensional pipeline in coal preparation plant, the searched path does not meet the requirements of pipeline design. In order to solve the above problems, an automatic pipeline layout method for coal preparation plant based on optimized A^* algorithm is proposed. Based on the pipeline layout rules of coal preparation plant, the layout space model of coal preparation plant is established. The grid and numerical processing are carried out on the layout space model. Aiming at the problem that the path searched by the A^* algorithm has excessive bending, the evaluation function of the A^* algorithm is optimized. To solve the problem of the slow search speed of the A^* algorithm, dynamic weight are introduced into the evaluation function. Aiming at the problem that the pipeline path searched by the A^* algorithm after the above optimization will bypass the required equipment, the direction-oriented strategy is introduced to improve the engineering practicability of pipeline layout. To improve the A^* algorithm's operation efficiency, the Open table's array structure is replaced with the minimum binary heap structure. The simulation result shows the following points. ① After optimizing the evaluation function of the A^* algorithm, the bending times of the pipeline path are reduced by about 80%. The ben is right angle, which accords with the actual situation of the pipeline layout in the coal preparation plant. After introducing the dynamic weight, the operation efficiency is improved and the path quality can be guaranteed. ② The path length of the pipeline before and after the direction-oriented strategy is introduced has no change. The lengths meet the basic constraint rule of the pipeline layout of the coal preparation plant. After the introduction of the direction-oriented strategy, the pipeline is more likely to be planned near the equipment with specific requirements for the pipeline. And the pipeline has a tendency to be arranged side by side. This indicates that the pipeline layout after the introduction of the direction-oriented strategy meets the requirements of the optimal overall layout, and is more consistent with the coal preparation engineering application. ③ The efficiency of A^* algorithm after Open table optimization is improved obviously. The longer the pipeline path and the more obstacles in the middle, the more significant the efficiency improvement of the A^* algorithm. The software system of automatic pipeline layout in the coal preparation plant is designed and developed. The application example of the optimized A^* algorithm is verified. The results show that the optimized A^* algorithm improves the efficiency and quality of piping design in the coal preparation plant, and has better visibility.