Abstract: Virtual reality technology provides an effective method to assembly module fixture.Because of universal and normative characteristic of module fixture，marked method can be the base of precise position and assembly relation.As the geometry assembly relation base of the fixture module in VR，mark is built on the function surface，and oriented the fixture based on the mark.The system manages the database as three layers：part，subassembly and instance，and the restriction relation is built on the base of mark.Using the mark，design efficiency is improved and design knowledge and experience can be saved and reused.A example is used in virtual assembly sysyem.

摘要： 虚拟环境为组合夹具的虚拟装配提供了有效的技术手段。针对组合夹具通用化、标准化的特点，采用“标记”的方法作为虚拟环境中元件精确定位和装配对的装配关系建立的基础。“标记”具有几何意义清晰、简便高效的特点，在虚拟环境中是组合夹具元件装配关系建立的几何基础，针对元件的功能表面建立“标记”，并以“标记”作为装配定位的基础，实现了虚拟环境中组合夹具的装配。系统采取夹具元件、组件、实例三层数据库结构进行管理，以标记作为约束建立装配关系，提高了设计效率，利于设计知识和设计经验的保存和在利用。在自主开发的虚拟装配系统中，对相关的方法和技术进行了实例验证。