Computer simulation is the main method to predict and control the micro-geometry and surface roughness of the machined surface. This paper takes the ball end milling cutter as the research object. Through the establishment of the ball end milling mathematical model, the ball end milling surface micro-geometry simulation algorithm is given, and the corresponding milling surface is developed based on the discrete method with the help of MATLAB software. Shape simulation system. Based on this simulation system, the influence of multi-parameters such as ball-end milling cutter cutting parameters and tool geometric parameters on the micro-geometric morphology and roughness of the machined surface is studied, which provides a basis for the reasonable selection of cutting parameters and tools in actual machining.