Abstract: According to the special situation of optoelectronic mast system working in parking state, a method for correcting azimuth of optoelectronic mast based on inertial navigation system (INS) calibrated by optoelectronic system was researched. The optoelectronic system was utilized to regularly aim a static target, and the reference azimuth was got to correct the azimuth error of the INS of optoelectronic system.Then the divergence of the azimuth error of the INS was restrained to improve the azimuth accuracy of the photoelectric system under a long time work. The results of experiment show that, under the situation of 0.06° equivalent azimuth error caused by the mast swing interference when it aiming the target and using STIM300 as the IMU, the INS azimuth error is 0.059° in 60 min using the correction method proposed and 1.14° in 31 min without correction.