Abstract: A device for separating and sequestrating carbon dioxide coupled with cold storage in mixed gas via hydrate method, which belongs to the technical field of application of natural gas hydrates includes a gas compression device, a refrigeration cycle device, a hydrate formation/decomposition device, a hydrate cold storage device, a water circulation device and a sensing and monitoring device; taking the separation and sequestration of biogas as an example, the refrigeration cycle device enables the cooling of biogas, decomposition of gas at all levels, hydrate, and circulating water to provide the low-temperature conditions required for hydrate formation; the hydrate cold energy storage device can fully use the latent heat of hydrate phase change to provide the required cooling capacity on the user side; the water circulation device can realize the recycling of decomposition water to ensure the continuous formation of hydrate.