Aiming at the requirements of optical high-precision angle measurement technology,a high-precision angle measurement method based on laser self-mixing interference technology is proposed.A system model of high-precision measurement angle of laser self-mixing interference technique is established.The interference fringe counting method is used to analyze the variation of the length of the outer cavity when the target object has an angular change.According to the laser triangulation measurement principle,the angle of rotation of the target object is obtained.Thereby constructing an accurate angle measuring system.The experimental results show that the measurement system can achieve measurement accuracy of (±3.1×10-3)° within ±0.4° angle range,which has obvious advantages such as high precision and high speed.It is a useful supplement to the existing high-precision angle measurement technology.