The invention discloses a heat management device for a power battery in a large temperature difference environment. The device comprises an auxiliary battery, an electric heating film heating device,a paraffin energy storage device, a heat tube heat-dissipating structure and a processor module, wherein the electric heating film heating device and the heat tube heat-dissipating structure are uniformly embedded between battery packs; the paraffin energy storage device is tightly arranged at the periphery of the power battery pack and conducts heat with the power battery pack; the auxiliary battery is used for supplying power to the electric heating film heating device and a control module; and the processor module controls on and off of the electric heating film heating device by detectingthe temperature of the power battery. According to the device, the power battery of an automobile can be still in a normal working temperature range in extremely high and low outer environmental temperatures, so that the service life and the service performance of the battery are ensured, and the device has the advantages of wide adaptability, simple structure and the like.