Method and device for calibrating size effect error of accelerometer

The invention provides a method and a device for calibrating a size effect error of an accelerometer. The method comprises the following steps: firstly preheating a strapdown inertial navigation system, and acquiring output data of a gyroscope and the accelerometer in the system; then calibrating the gyroscope, and compensating an gyro error; then rotating the system at different angular velocities, and acquiring a system horizontal velocity error when the system reaches the same position; and acquiring the size effect error of the accelerometer according to the change of the system horizontal velocity error. The method and the device can achieve system-level precise calibration of the size effect error of the accelerometer so as to furthest separate the size effect error of the accelerometer from other error items of the accelerometer and improve the navigation precision and efficiency of the system.