A freezing method using a gas as a refrigerant, comprising: step 1: using a colorless, tasteless, and non-toxic liquid gas or supercritical gas as a refrigerant for freezing； step 2: immersing a product to be frozen in the liquid gas or the supercritical gas until the center temperature of the product to be frozen reaches the temperature of a freezing stage； and step 4: taking out the product to be frozen and transferring it to a frozen storage low temperature environment for storing. A multi-stage freezing method using a gas as a refrigerant, comprising: step 1: dividing the freezing process for a product to be frozen into at least two freezing stages； step 2: sequentially performing freezing operations corresponding to each of the freezing stages on the product to be frozen； and step 3: transferring, after balancing the pressure of the product to be frozen with the atmospheric pressure, the product to be frozen to the frozen storage low temperature environment for storing.
