NOVELTY - A two-section single-circulation mixed freezing medium natural gas is liquefied by performing two-section compression cooling on mixed freezing medium, performing first gas and liquid separation, and obtaining gaseous and liquid freezing medium. The mixed freezing medium comprises (mass%) methane (16-22), ethylene or ethane (33-39), propane (15-21), isopentane (12-18), and nitrogen (8-14).    USE - Method for the liquefaction of a two-section single-circulation mixed freezing medium natural gas (claimed).    ADVANTAGE - The method has simple technical flow, high liquefying efficiency, and low energy consumption.    DETAILED DESCRIPTION - Liquefaction of a two-section single-circulation mixed freezing medium natural gas comprises:    (A) performing two-section compression cooling on mixed freezing medium, performing first gas and liquid separation, and obtaining gaseous and liquid freezing medium;    (B) enabling the liquid freezing medium to enter a cold box to cool to throttle and cool, returning the cold box to supply cold component with high temperature position;    (C) enabling the gaseous freezing medium to enter the cold box to cool to be at low temperature, throttling and cooling, returning the cold box to supply the cold component with low temperature position, converging with liquid freezing medium returning the cold box after the throttling, and supplying the cold component with high temperature position;    (D) performing two-section compression cooling on the mixed freezing medium supplying the cold component, and entering the next circulation; and    (E) enabling the natural gas to enter the cold box to cool, throttling, and obtaining the liquefied natural gas product, where the mixed freezing medium comprises (mass%) methane (16-22), ethylene or ethane (33-39), propane (15-21), isopentane (12-18), and nitrogen (8-14), and the two-section compression cooling is performed by compressing the mixed freezing medium at 600-1000 kPa, cooling at 25-45 degrees C or at room temperature, performing secondary compression to be 3500-4500 kPa, and cooling at 25-45 degrees C or at room temperature.    An INDEPENDENT CLAIM is included for a natural gas liquefying equipment.