Aiming at the problems of time-consuming, low accuracy and high energy consumption existing in the detection of the state of health (SOH) of the decommissioned power battery at current stage, this paper proposes a method to quickly predict the state of charge (SOC) and SOH based on electrochemical impedance spectroscopy (EIS). Through testing and analyzing the EIS of decommissioned lithium iron phosphate power batteries in different SOH at different SOC and different temperatures, an EIS equivalent circuit model is constructed. Then, the relationship between the constant phase component parameters and the SOC and SOH of the decommissioned power battery is used to establish a mathematical model to realize the rapid estimation of the SOC and SOH of the decommissioned power battery. Verification experiments show that using this method can greatly reduce to less than 20 min, save energy source and achieve rapid estimation of the battery with unknown SOC and SOH, and the prediction error is within 4% .