The invention discloses a two-stage self-overlapped subzero refrigeration circulating system achieving the synergistic action of duplex injectors and a circulating method. Inlets of a compressor, a condenser and a gas-liquid separator I of the system are connected in sequence, saturated gas obtained through the gas-liquid separator I passes through an evaporation condenser I to enter a gas-liquidseparator II, and saturated liquid obtained through the gas-liquid separator I enters a nozzle of the injector II. Gas obtained through the gas-liquid separator II passes through an evaporation condenser II, a heat regenerator, a throttling valve and an evaporator to be refrigerated and then enters a secondary flow-in opening of the injector I. Liquid obtained through the gas-liquid separator II enters a nozzle of the injector I to be mixed with secondary flow from the evaporator and boosted, the liquid enters the injector II to be injected by the saturated liquid from the gas-liquid separatorI and then sequentially enters the evaporation condenser II and the evaporation condenser I, and finally the liquid returns to the compressor. Expansion work of the liquid throttling process is fullyrecycled by the duplex injectors, the gas suction pressure of the compressor is improved step by step, and the overall performance of the compressor and the system is improved.