Abstract: Aiming at the problems that existing methods for estimating state of charge (SOC) of explosion-proof lithium battery of mine locomotive has large cumulative errors which are affected by battery model accuracy, a SOC estimation algorithm based on correcting Ahh-total integration method with segmented open-circuit voltage is proposed. This method corrects the initial SOC value by the open-circuit voltage, and overcomes the accumulated error by periodic correction, so as to ensure the accuracy of the algorithm. The hardware design of the algorithm is implemented by using smart battery monitoring chip MC33771. The experiment shows that this method is suitable for the explosion-proof lithium battery management system of mining locomotive.