Laser semi-active seeker for UAV is characterized by maneuvering flexible,attack range wide and hit precision high.It plays an important role in the guidance weapon field.To improve sensitivity,dynamic range and resistance stray light performance of photoelectric receive system,through the analysis of the Quad Avalanche Photodiode(QAPD)photoelectric receive system,the front-end signal conditioning circuit and the back-end signal processing circuit are designed.The experimental results show that the system sensitivity reaches 100nW and dynamic range is 45dB,and the peak tracking maximum error ratio is 1.06.System can work normally in stray light environment,and closed ring control is realized.The research results have certain application value to the design of photoelectric receiving circuit.