Precision green laser trimming system was Introduced. The system composition structure was analyzed. The system includes laser system, laser focus and optical localization system, precise numerical control system and automation test system. The application of green laser trimming in diaphragm pressure sensor was described. The main craft of green laser trimming which is used in the film pressure sensor was analyzed, the key craft is the laser energy real-time control and laser beam size. Through the high performance laser, focus, supervisory and precise motion control system, trimming technology was successfully applied in the film pressure sensor production. Sensor’s zero point error has been controlled between -80～+80 μV, and zero temperature drift is smaller than 0.02% ℃, the non-compensatory of sensor was achieved.