The invention discloses an air conditioning system which comprises a compressor, a four-way valve, an indoor heat exchanger, a first pipe section, a second pipe section, a third pipe section, a fourth pipe section and a fifth pipe section, wherein a first one-way valve is arranged on the first pipe section, so that a refrigerant flows from the other end of the first pipe section to one end of the first pipe section; a second one-way valve is arranged on the second pipe section, so that a refrigerant flows from one end of the second pipe section to the other end of the second pipe section; a third one-way valve is arranged on the third pipe section, so that a refrigerant flows from the other end of the third pipe section to one end of the third pipe section; a fourth one-way valve is arranged on the fourth pipe section, so that a refrigerant flows from one end of the fourth pipe section to the other end of the fourth pipe section; and at least part of the fifth pipe section is in contact with a modular heat dissipator of the air conditioning system. According to the air conditioning system disclosed by the invention, by arranging a plurality of one-way valve structure, the pipeline is simpler, and the problem that the modular heat dissipator is condensed is better improved.