Battery pack heating method in low-temperature environment and battery pack

The invention relates to the technical field of power batteries, in particular to a low-temperature environment battery pack heating method and a battery pack, the battery pack comprises a first battery and a second battery, and the low-temperature performance of the first battery is higher than that of the second battery. Two heating electrodes are formed on the current collector of the second battery, and the positive electrode and the negative electrode of the first battery are respectively connected and conducted with the two heating electrodes; and after the two heating electrodes are electrified, the temperature of the current collector is increased, so that the internal temperature of the second battery is increased. In a low-temperature environment and before the battery pack is used, the second battery is charged through the first battery, the temperature of the current collector in the second battery is increased under the Joule effect, and when the temperature of the second battery reaches a set va