The invention discloses an oxygen supply fermentation system. The system comprises a fermentation tank, a gas supply device, a circulating pump and a jet aerator, wherein the top space in the fermentation tank forms a gas collection chamber; the gas supply device is arranged in the gas collection chamber; the input end of the circulating pump is communicated with the middle space of the fermentation tank; the output end of the circulating pump is communicated with the jet aerator; meanwhile the jet aerator is communicated with the gas supply device; the jet aerator is arranged at the lower middle part of the fermentation tank; a gas vent is formed in the top of the tank body of the fermentation tank; a vent valve is arranged in the gas vent. The system realizes rapid homogenization of gasphase and liquid phase, produces a small quantity of bubbles during a mixing process, and is high in dissolved oxygen coefficient, mixing efficiency and degree of homogenization, and small in contamination probability. In addition, the system is simple in structure, does not need air compressors and stirrers, is low in power consumption and comprehensive cost, and convenient and efficient to use,and has a good market prospect.