The invention discloses a valve element assembly of a pilot-controlled check valve. The valve element assembly comprises a screw sleeve, a liquid inlet sleeve, a valve seat, a valve sleeve, a large valve element arranged inside the valve sleeve, a small valve element arranged inside the large valve element, a differential valve element movably arranged inside the valve sleeve and used for controlling the large valve element to move, and a pressure adjusting mechanism arranged inside the valve sleeve and used for applying elastic acting force to the differential valve element. According to thevalve element assembly of the pilot-controlled check valve, by arranging the differential valve element inside the valve sleeve, automatic pressure relief of the pilot-controlled check valve can be realized; by arranging the pressure adjusting mechanism, the working pressure of the pilot-controlled check valve can be adjusted so that the pilot-controlled check valve can meet the working requirements of the different pressure, and universality of the pilot-controlled check valve is improved; and the pressure adjusting mechanism is arranged inside the valve sleeve, thus the compactness of the overall structure of the valve element assembly is improved, the integration level of the valve element assembly is high, and disassembly and assembly are convenient.