Abstract: For the problem that accumulative error was easy to occur in estimation for state of charge (SOC) of mine-used energy storage battery based on ampere-hour integration method, an accurate estimation method for SOC of mine-used energy storage battery based on improved ampere-hour integration method was put forward. In the method, temperature correction coefficient, aging degree correction coefficient and charging-discharging ratio correction coefficient are introduced to correct battery capacity, so as to realize accurate estimation of battery SOC. Battery terminal voltage is used to replace open circuit voltage when battery SOC is from 0 to 15% or from 90% to 100%, then the estimation results obtained by the improved ampere-hour integration method are corrected real-timely. The experimental results show that the method can improve estimation precision of SOC of mine-used energy storage battery, and the estimation error is within ±3%.