Abstract: In order to improve the production efficiency of the coal washing process, increase the service life of the washing equipment, maximize the potential production capacity of the screening equipment in the coal preparation plant, improve the rationality of the screening process, comprehensively improve the relaxation screen screening system and reduce the wear rate of the screen surface due to the high screening efficiency, a measure of adjusting the performance parameters of the relaxation screen is proposed to optimize the screening efficiency and reduce the wear of the screen surface. The flexible sieve plate is discretized to reduce the complexity of the simulation process of the flexible sieve plate, and the multi-body dynamics simulation and the discrete element method are used to numerically simulate the sieving process of the sieve surface, and the performance parameters of the relaxation sieve are obtained. : The influence law of relaxation frequency, sieve surface inclination, and relaxation amount on screening efficiency, and considering the correlation coefficient method and the significance test method comprehensively, it is determined that the relaxation amount is a non-key factor affecting the screening efficiency. On the basis of summarizing the wear law of the relaxation sieve screening process, the influence law of the sieve surface relaxation amount on the wear depth in the simulation process is obtained through the Relative Wear and Archard Wear models. Based on the dual effects of relaxation on screening efficiency and wear depth, the linear weighting method was selected for multi-objective optimization of screen surface performance, and the performance parameters of the screen surface that ensured the highest screening efficiency and minimum wear depth were obtained and verified by simulation. The research results show that: the screening efficiency decreases with the increase of the inclination angle of the screen surface, and the greater the relaxation amount and the relaxation frequency, the change rule increases first and then decreases; After increasing, the trend decreases. Considering the screening efficiency and the wear of the screen surface comprehensively, the optimal performance parameters of the screen surface are obtained, that is, when the relaxation amount of the screen surface is selected as 5 mm, the screening efficiency can reach 80.85%, and the wear depth of the screen surface It is only 0.051 6 mm, compared with the optimal screening efficiency, the wear of the screen surface is reduced by 26.5%, while the screening efficiency is only reduced by 0.48%, which can significantly reduce the wear of the screen surface under the condition that the screening efficiency is less affected. It shows that the sieving performance of the optimized relaxation sieve has been significantly improved. The adoption of the above technical solutions can effectively improve the performance parameters of the screening link in the washing process, improve the production capacity of the equipment, and provide technical support for the intelligence of the washing system of the coal preparation plant.