The invention relates to an SOC/SOH/SOP joint estimation method of a power battery based on an equivalent circuit model and belongs to the technical field of battery management. The method comprises the following steps that the type and model of the power battery are selected first, corresponding technical parameters are obtained, and the equivalent circuit model of the battery is established; then, a trickle charge-discharge experiment and an HPPC experiment are conducted on the detected battery at a specific temperature to obtain battery characteristic parameters; the relation between OCV and SOC of the battery is further established according to experiment data, and meanwhile parameters in the battery model are identified and fed back into the model; finally, sensor data is imported into a joint estimation algorithm, model parameters are updated through an mMHE method and a rolling-window online parameter identification method, and online joint estimation of SOC, SOH and SOP is realized. By adopting the method, accurate estimation of SOC, SOH and SOP is achieved under different time scales and the condition that certain operation speed is guaranteed.