A battery heating system, characterized by comprising a switch assembly connected to a battery pack, an inverter connected to the switch assembly, and a motor connected to the inverter; the inverter comprises a first-phase bridge arm, a second-phase bridge arm and a third-phase bridge arm connected in parallel, wherein each of the first-phase bridge arm, the second-phase bridge arm and the third-phase bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm are respectively provided with a switch module (P21, P23, P25 and P22, P24, P26) and a buffer module connected in parallel with the switch module to protect the switch module; a first-phase input terminal, a second-phase input terminal and a third-phase input terminal of the motor are connected respectively to a connection point of the upper bridge arm and the lower bridge arm in the first-phase bridge arm, a connection point of the upper bridge arm and the lower bridge arm in the second-phrase bridge arm and a connection point of the upper bridge arm and the lower bridge arm in the third-phase bridge arm; and the inverter further comprises a motor controller for outputting driving signals to the switch module of a target upper bridge arm and the switch module of a target lower bridge arm to control the switch module of the target upper bridge arm and the switch module of the target lower bridge arm to be periodically turned on and off so as to generate an alternating current, wherein the switch module of the target upper bridge arm is the switch module of the upper bridge arm of any bridge arm among the first-phase bridge arm, the second-phase bridge arm and the third-phase bridge arm, and the switch module of the target lower bridge arm is the switch module of the lower bridge arm of at least one of the bridge arms except the bridge arm where the switch module of the target upper bridge arm is located. the inverter comprises a first-phase bridge arm, a second-phase bridge arm and a third-phase bridge arm connected in parallel, wherein each of the first-phase bridge arm, the second-phase bridge arm and the third-phase bridge arm comprises an upper bridge arm and a lower bridge arm, the upper bridge arm and the lower bridge arm are respectively provided with a switch module (P21, P23, P25 and P22, P24, P26) and a buffer module connected in parallel with the switch module to protect the switch module; a first-phase input terminal, a second-phase input terminal and a third-phase input terminal of the motor are connected respectively to a connection point of the upper bridge arm and the lower bridge arm in the first-phase bridge arm, a connection point of the upper bridge arm and the lower bridge arm in the second-phrase bridge arm and a connection point of the upper bridge arm and the lower bridge arm in the third-phase bridge arm; and the inverter further comprises a motor controller for outputting driving signals to the switch module of a target upper bridge arm and the switch module of a target lower bridge arm to control the switch module of the target upper bridge arm and the switch module of the target lower bridge arm to be periodically turned on and off so as to generate an alternating current, wherein the switch module of the target upper bridge arm is the switch module of the upper bridge arm of any bridge arm among the first-phase bridge arm, the second-phase bridge arm and the third-phase bridge arm, and the switch module of the target lower bridge arm is the switch module of the lower bridge arm of at least one of the bridge arms except the bridge arm where the switch module of the target upper bridge arm is located.