与腔内运行线偏振光的抖动陀螺相比，腔内运行圆偏振光的零闭锁激光陀螺对磁场更为敏感.为了减小零闭锁激光陀螺的磁敏感性，理论分析了其磁敏感特性.当左、右旋陀螺的比例因子修正相等时，陀螺零偏不随磁场的变化而变化，同时陀螺比例因子线性度也将得到改善.试验测试了零闭锁激光陀螺的磁敏感性，结果表明陀螺存在磁不敏感点.试验结果与理论分析吻合.与传统的被动磁屏蔽方法相比，通过主动控制使得零闭锁激光陀螺工作在磁不敏感点的方法对于降低该陀螺的磁灵敏度和提高准确度具有实用价值.

Compared to the dithered ring laser gyro with the linearly polarized light running in the cavity, the Zerolock Laser Gyro(ZLG) with the circularly polarized light running in the cavity is more sensitive to the magnetic field. In order to reduce the magnetic sensitivity of the ZLG, the magnetic sensitivity of the ZLG is theoretically analyzed. When the relative sacle factor corrections of left and right circularly polarized gyros are equal, the bias of the ZLG will not vary with the magnetic field. Further more, the linearity of relative scale factor correction will be improved. The magnetic sensitivity of the ZLG is experimentally tested, and the results indicate that the insensitivity point with respect to the magnetic field is existent, which is consistant with the theroretical analysis. Compared to the method of traditional passive magnetic shielding, the method of operating ZLG on the insensitive point by active control is proved to be of great practical value for reducing the magnetic sensitivity and improving the accuracy of the ZLG.