The invention discloses an SOC estimation method of an automobile power lithium battery. The method comprises the steps as follows: a, the method is started; b, when he shelving time is smaller than the set time T0, a step c is entered, otherwise a step d is entered; c, an SOC value during the use stoppage of the lithium battery is taken as a current SOC value; d, a real-time power lithium battery SOC value is obtained by the aid of a relation between open-circuit voltage and the SOC, and a step g is enter; e, when the lithium battery is dynamic, a step f is entered, otherwise, the step b is returned to; f, the SOC is estimated with an Ah integral method, and preliminary correction is performed; g, a difference value of the SOC value obtained in the step d and the SOC value estimated with the Ah integral method is judged, if the difference value is smaller than a set absolute value of e, and a step i is entered, otherwise, a step h is entered; h, the obtained SOC value corrects an initial SOC value of the Ah integral method; and I, the method is finished. According to the method, the SOC is corrected from different aspects, error accumulation caused by the Ah integral method for a long time is modified, and the SOC accuracy can be improved.