Augmented reality (AR) is a technology that computes the position and angels of cameras in real time, and supplements these with corresponding images. It aims to realize interaction between the virtual and actual worlds on screen. Virtual objects that don’t exist in the real environment are generated with the help of computer graphics and visualization technology. The virtual objects are then accurately "placed" in the real environment through sensing technology. Virtual objects are smoothly integrated with the real environment, with the help of display equipment, and a new environment with real sensory effects is presented to users. Therefore, the augmented reality system has the new characteristics of combination of virtuality with reality, real-time interaction and three-dimensional registration. It is widely used in visualization of building data model, military virtual training, entertainment and arts, etc.