The error of rotation table shafting error is the main factor that causes the horizontal attitude demodulation error ofsingle-axis rotation inertial system.To solve the problem, an online high-precision self-calibration method for rotation table shaftingerror is proposed, and the propagation model between rotation shaft declination and attitude demodulation error is analyzed anddeduced in detail.The error calibration method of shafting of turntable is designed.By using the output data of turntable Angleencoder and Inertial Measurement Unit (IMU) gyro, the high-precision calibration of shafting effectiveness of the method is verifiedby practical data.