Abstract: The design of squeeze casting process parameters is the key to the advantages of squeeze casting. At present, they are mainly determined by physical experiments and numerical simulations, with high cost, low efficiency and inconvenient observing the microscopic mechanism. Based on the unique advantages of molecular dynamics to explain the microscopic mechanism, a molecular dynamics-based squeeze casting forming mechanism simulation method was established, a 7075 aluminum alloy polycrystalline molecular casting model was constructed, and molecular dynamics software was used to simulate the forming process of squeeze process of the aluminum alloy; and the influence of process parameters on the performance and microstructure of castings was studied from a microscopic point of view, so that the optimal process parameters were achieved.This study result provides a new method for the design of squeeze casting process parameters and the selection of materials, which can save a lot of design time and resources.