The invention discloses a novel natural cooling resource refrigerating system and a control method thereof. The system comprises a condenser, a liquid accumulator, a freezing medium circulating pump, an electronic expansion valve, an evaporator and a refrigeration compressor. The evaporator, the compressor, the condenser, the liquid accumulator, the freezing medium circulating pump and the electronic expansion valve are connected in sequence to form a circulation loop, wherein the evaporator and the condenser are connected through a first by-pass pipeline, and the liquid accumulator and the electronic expansion valve are connected through a second by-pass pipeline; the refrigeration compressor, the condenser, the liquid accumulator, the electronic expansion valve and the evaporator form an air cooling water chilling unit refrigeration cycle system, and the condenser, the liquid accumulator, the freezing medium circulating pump and the evaporator form a natural cooling resource refrigeration cycle system. Compared with the prior art, a freezing medium is used as a circulating medium, so the novel natural cooling resource refrigerating system has the advantages of an ethylene glycol scheme and a pure water scheme, and no special antifreeze process is needed, the cost can be reduced and the heat exchange efficiency and the convenience of maintenance are improved.