By taking a micro-gas turbine engine developed by MIT as a prototype,the theory and process of virtual assembly technology were depicted,and its three-dimensional micro-combustor was constructed successfully in SolidWorks after analyzing the traditional approaches to geometric modeling in Computing Fluid Dynamics(CFD).The results show that the created method for micro-combustor based on the virtual assembly technology is prior to the traditional modeling approaches,which can decrease the cost of products in Power MEMS and can promote their industrialization.