The invention discloses an air-conditioning system and an air-injection degree of superheat regulating system. The air-conditioning system comprises a compressor (6), a condenser (4) and a main loop expansion valve (3), and further comprises a heat storage device (5), a super-cooler (9), a first enthalpy increasing pipeline, and an enthalpy increasing expansion valve (2), wherein the super-cooler (9) is arranged between the condenser (4) and the main loop expansion valve (3); the first enthalpy increasing pipeline penetrates through the super-cooler (9), passes through the heat storage device (5), and is connected to a gas supplementing hole of the compressor (6); and the enthalpy increasing expansion valve (2) is arranged on the first enthalpy increasing pipeline. According to the air-conditioning system provided by the invention, a fluid flows into the compressor after heat of the fluid is absorbed by the heat storage device, so that the problem that the air-injection degree of superheat of the enthalpy increasing fluid flowing into the compressor is too low or is a negative value is effectively avoided, and therefore, the control on the air-injection degree of superheat is improved, and the operation reliability of the compressor and the air-conditioning system is guaranteed.