For a high precision pulse laser rangefinder,the use of automatic gain control (AGC) technology can greatly extend dynamic range of the receiver without loss of distance accuracy.In this paper,the receiver model as well as the means to adjust the gain is discussed and analyzed.Based on this analysis,the dynamic range of gain control is calculated under the condition of high precision range finding.Then an AGC method of changing the gain based on the real-time measured amplitude of the signal and noise is proposed.The experimental results show that the receiver with an AGC circuit can adapt to changes in the power of the returning signal and benefited from this,the precision of wide dynamic range distance measurement will be ensured.