For the error of the accelerometer leads to inaccurate calculation of the vehicle speed in the MEMS accelerometer-based maglev train speed calculation scheme, a new method of error calibration was proposed. Firstly, the error model of the accelerometer was established from two aspects: installation error and inherent error. Secondly, an online solution method based on adaptive damped least squares was proposed for the installation error model. Finally, a field test was carried out on a domestic medium-low speed maglev train. The test results showed that the proposed method can effectively calibrate the error of the accelerometer, and can meet the speed calculation requirements of maglev train.