The static and dynamic characteristics calculating of the whole machine structure by finite element method lead to dense grid nodes, which is not conducive to rapid quantitative analysis. Therefore, a simplified model and the corresponding static and dynamic characteristics are needed. This paper presents a simplified model using key nodes kept principle and a corresponding software which reads data from resulting data file, extracts information such as coordinates, static and dynamic displacement of relevant nodes from reading data and draws simplified models of the whole machine structure and static and dynamic deformation of it. Take XK173 Vertical Milling Machine as the case research object, establish a complete machine model, analyze the static and dynamic characteristics and reproduce that using simplified model by software. The result shows that the Vertical Milling Machine nodes are reduced from the original 153 238 nodes to156 nodes. It well preserves machine structure and static and dynamic characteristics, and lays foundations for simplifying follow-up quantitative analysis.