An embodiment of the invention discloses a motor system and a control method thereof. The motor system comprises a motor, a power battery and a control module, the power battery is electrically connected with the motor, the control module is electrically connected with the power battery and the motor, and the control module is used for detecting residual capacity and temperature of the power battery in real time and controlling the motor to be started according to low power and a torque mode required by a driver when detecting that the residual capacity of the power battery is smaller than orequal to a first residual capacity threshold value and/or the temperature of the power battery is smaller than or equal to a first temperature threshold value. According to the motor system, when theoutput power of the battery is low, a vehicle rapidly starts, and the starting performance of the electric vehicle is enhanced.