A power battery heating method, configured for heating a power battery of a vehicle, the power battery heating method comprising: obtaining a current temperature value of the power battery, and determining that the current temperature value of the power battery is lower than a preset temperature value; obtaining heating power of the power battery; obtaining a preset quadrature-axis current, and obtaining a corresponding preset direct-axis current according to the heating power of the power battery, wherein a value of the obtained preset quadrature-axis current is a quadrature-axis current value that causes a torque value outputted by a three-phase alternating current motor to fall within a target range, and zero is not comprised in the target range; controlling an on/off status of a power device in a three-phase inverter, so that the three-phase alternating current motor generates heat according to heating energy provided by a heating energy source, to heat a coolant flowing through the power battery, and controlling, according to the preset direct-axis current and the preset quadrature-axis current, the three-phase inverter to adjust a phase current of the three-phase alternating current motor in the heating process, characterized in that a direction of the preset direct-axis current changes periodically in the heating process; wherein the heating energy source is an external charging device; and wherein the heating process comprises a plurality of heating periods, each heating period comprises two preset heating durations and two preset switching durations, the preset direct-axis current is in a positive direction and has a constant amplitude value within the first preset heating duration, the preset direct-axis current is in a negative direction and has a constant amplitude value within the second preset heating duration, the preset direct-axis current changes from the positive direction to the negative direction and has a constantly changing amplitude value within the first preset switching duration, and the preset direct-axis current changes from the negative direction to the positive direction and has a constantly changing amplitude value within the second preset switching duration; and the preset heating duration is greater than the preset switching duration. obtaining a current temperature value of the power battery, and determining that the current temperature value of the power battery is lower than a preset temperature value; obtaining heating power of the power battery; obtaining a preset quadrature-axis current, and obtaining a corresponding preset direct-axis current according to the heating power of the power battery, wherein a value of the obtained preset quadrature-axis current is a quadrature-axis current value that causes a torque value outputted by a three-phase alternating current motor to fall within a target range, and zero is not comprised in the target range; controlling an on/off status of a power device in a three-phase inverter, so that the three-phase alternating current motor generates heat according to heating energy provided by a heating energy source, to heat a coolant flowing through the power battery, and controlling, according to the preset direct-axis current and the preset quadrature-axis current, the three-phase inverter to adjust a phase current of the three-phase alternating current motor in the heating process, characterized in that a direction of the preset direct-axis current changes periodically in the heating process; wherein the heating energy source is an external charging device; and wherein the heating process comprises a plurality of heating periods, each heating period comprises two preset heating durations and two preset switching durations, the preset direct-axis current is in a positive direction and has a constant amplitude value within the first preset heating duration, the preset direct-axis current is in a negative direction and has a constant amplitude value within the second preset heating duration, the preset direct-axis current changes from the positive direction to the negative direction and has a constantly changing amplitude value within the first preset switching duration, and the preset direct-axis current changes from the negative direction to the positive direction and has a constantly changing amplitude value within the second preset switching duration; and the preset heating duration is greater than the preset switching duration.