Disclosed is a portable device for aiding low temperature high power output of a battery pack, the device including a primary loop and a control unit, in which: the primary loop is configured as a working loop of the battery pack and comprises a power resistor, herein two ends of the power resistor are electrically connected with the positive/negative terminal of the battery pack respectively, and the battery pack discharges at low temperatures through the power resistor so that an internal temperature of the battery pack rises; and the control unit is configured to control on/off of the primary loop.