The invention provides a dual-purpose box capable of storing and converting energy during an off-peak electricity consumption period. The dual-purpose box comprises an energy storage box body, coiled pipes and electric heat pipes. The dual-purpose box is characterized in that the energy storage box body is filled with softened water; the wall of the energy storage box body is provided with an energy storage box upper water inlet/outlet and an energy storage box lower water inlet/outlet; the energy storage box body is internally provided with the coiled pipes which are filled with refrigerants, and refrigerant inlets and refrigerant outlets of the coiled pipes are led to the outside of the energy storage box body; and the electric heat pipes are arranged on the lower portion of the interior of the energy storage box body and connected with a power line penetrating out of a power line pipe. According to the dual-purpose box capable of storing and converting the energy during the off-peak electricity consumption period, electric energy in the nighttime off-peak electricity consumption period serves as an energy source, and the electric energy in the nighttime off-peak electricity consumption period is stored, so that energy converting of media in the energy storage box body is achieved; in winter, the softened water in the energy storage box body is heated, and accordingly the heat required by all-day heating and domestic water is stored in the energy storage box body in a hot water mode and used all day long; and in summer, the refrigerants in the coiled pipes are refrigerated through a refrigerating machine, so that the cold quantity required by an air conditioner all day long is stored in the energy storage box body in an ice water mode and used as needed.