In order to achieve the green preparation of manufactured sand, and improve the quality of manufactured sand. The numerical simulation of coarse crushing, medium-fine crushing, screening and transportation process based on discrete elements was carried out. The key parameters of manufactured sand preparation were optimized, and the influence rules on the quality of manufactured sand were clarified. The results showed that the rock crushing efficiency can be improved, the energy consumption can be reduced, the particle size distribution of the rock after crushing can be optimized, and the wear of the rock to the equipment can be reduced by adjusting the size of the discharge port of the crushing equipment. The tilt angle of the vibrating screen in the screening stage should be between 10 and 15 degrees, and the layout angle of the conveyer belt should be 16 degrees during the transport stage. In addition, the research has been applied in large-scale manufactured sand production enterprises, which provides scientific support for green high-quality preparation of manufactured sand.