According to the reasons of three-dimensional (3D) angle deformation of large structure in engineering applications and measurement requirements, the research states of optical small angle measurement method used in engineering area are described and analyzed. Some methods such as auto-collimation, polarization light, light source target, moiré fringe, image shape deformation and photography and videography are introduced. Comparing with the characteristics of the methods, the problems and development of optical 3D angle deformation measurement technology are discussed.