Abstract: Laser measurement based on triangulation is a traditional method for measuring displacement. Along with the development of Lasers, photoelectric detectors and computers, triangulation method has made much progress and found more and more applications. Several laser methods based on triangulation for measuring displacement are surveyed and discussed in this paper. Laser triangulation measurement techniques can be mainly divided into two types,the normal incidence and oblique incidence, based on the incidence way of the light.The measurement principles of these two kinds are introduced respectively and their characteristics are compared. Some application examples and the development trends of high precision laser displacement sensor based on triangulation are given at the end of this paper.