Abstract: The Research on Desktop Virtual Assembly System for Two-stage Helical Cylindrical Gear Reducer Based on DOF Node LI Yan-wen, DONG Xiu-cheng, LI Chang-long (School of Electric and Information Engineering, Xihua University, Chengdu 610039 China) This paper takes advantages of three-dimensional modeling software SolidWorks to draw all spare parts' models of a two-stage helical cylindrical gear reducer and simplifies and reorganizes the models with the help of Multigen Creator.Thus the characteristics of the models can be shown clearly by making full use of special function nodes of Multigen Creator. Without precise location information, spare parts localization method which avoids too many constraints' impact on real time is proposed based on DOF nodes. The assembly process makes full use of limited desktop peripherals. The system is simply constructed, as well as practical.