The application of super capacitor and battery in parallel can improve the low temperature starting performance of locomotive. In order to improve the starting performance (higher starting torque) of automobile in cold weather, supercapacitor is of great significance. When the temperature is - 20 ℃, the performance of the battery is greatly reduced, it is likely that the battery can not be started normally or it needs to be started several times. However, when the super capacitor can be paralleled with the battery at - 40 ℃, it only needs one ignition, so its low temperature advantage is very obvious.