Abstract: The present disclosure provides an apparatus and a method for hydrate-based wastewater treatment and cold storage. The apparatus for hydrate-based wastewater treatment and cold storage includes a water chilling unit, a hydrate-based cold storage tank, an airflow disturbance device, a water layer positioning system, a spraying system, a suction filtration system, a heat exchange system, and a system monitoring device. The water chilling unit provides a secondary refrigerant at a low temperature. The secondary refrigerant flows through an evaporator coil in the hydrate-based cold storage tank for heat exchange. The airflow disturbance device induces hydrate nucleation. The water layer positioning system positions a contact surface between a water layer and a hydrate former after hydrate decomposition to facilitate drawing and separation of the treated upper water layer. The spraying system and the suction filtration system enhance the solid-liquid separation efficiency to improve the removal rate of pollutants.