For mining machinery parts with high performance requirements,its manufacturing process should be strictly controlled, so it is very important to obtain processing information and control the processing process in real time for optimizing the processing technology. The traditional MBD method can be used to define the part information into the 3D model, but it can’〖KG-*2〗t be used to monitor and control the machining process in real time. Therefore, a dynamic modeling method for complex parts based on digital twin was proposed, which could be used to build a multi physical and multidimensional digital twin model of mining machinery parts processing process. Through this method, the dynamic model based on digital twin was established, including geometric model, process model and other sub models. These models can interact with each other, and can show the dynamic changes of mining machinery parts processing process and online optimization of manufacturing process in real time, which provides ideas for process optimization.