The present disclosure provides a battery heating system and a control method thereof. The battery heating system includes a main positive switch, a main negative switch, an inverter, a motor, and a battery management unit. The inverter includes a first phase bridge arm, a second phase bridge arm and a third phase bridge arm connected in parallel. A motor controller in the inverter is configured to output a drive signal to a target upper-bridge-arm switch unit and a target lower-bridge-arm switch unit, so as to control the target upper-bridge-arm switch unit and the target lower-bridge-arm switch unit to be periodically turned on and off. The battery management unit is configured to collect state parameters of the battery pack. When the state parameters of the battery pack meet preset heating conditions, a control signal is sent to the motor controller to control the motor controller to output the drive signal.