The invention provides a battery SOC calibration method. The method comprises the following steps of S1, powering on a system, reading the storage time and a storage SOC value in a readable memory, judging whether the standing time meets a threshold value or not, judging whether a platform area exists or not if the standing time meets the threshold value, starting OCV-SOC table look-up calibrationif the standing time meets the threshold value, and then carrying out the step S2, otherwise, directly carrying out the step S2; S2, judging whether a charging mode is adopted or not, if yes, readingthe current SOC value, the charging current, the charged time and the charging highest battery cell voltage, executing the step S3, otherwise, executing the step S2; S3, judging and calibrating a Dq/Dv relationship; S4, carrying out static voltage slope calibration; and S5, performing charging terminal voltage calibration. The SOC calibration method is advantaged in that SOC calibration is carried out in three modes of Dq/Dv relation, charging terminal voltage and static voltage slope judgment in the charging process, calibration errors caused by the fact that the battery cell exists in a platform area are avoided, and therefore the SOC calibration method is suitable for SOC calibration of different types of battery cells.