Energy-saving start method of oxygen generator

The invention discloses an energy-saving starting method for an oxygen producing machine, wherein the method comprises the following steps: a, sweeping of a space division system; b, accumulation of liquid air of the space division system; and c, starting of an oxygen producing machine, wherein during the sweeping of a space division system in step a, the heating and the sweeping of the space division system are performed by adopting low pressure nitrogen in a pipe network; during the accumulation of liquid air of the space division system in step B, the expansion and the refrigeration of the space division system are performed by adopting the low pressure nitrogen in the pipe network; the starting of the oxygen producing machine in step c includes the starting of an air compression system, an air precooling system and a molecular sieve system; in step b, after a main condenser of a space division column reaches air liquefaction temperature, loxygen discharged by the main condenser is reversely charged into the main condenser before stoppage, so that the liquid level of the main condenser reaches a liquid level required at the step of adjusting purify; and in step b, the expanded nitrogen entering the space division system is repeatedly pumped, pressed and recycled. An air compressor does not start, and the sweeping of the space division system is performed by utilizing the nitrogen in the pipe network; the time and the energy consumption of the sweeping of the space division system are saved; the starting time of space division is greatly shortened; the power consumption is saved; and the commissioning time is shortened.