The invention relates to a single effect type lithium bromide refrigerating machine for an air separation device. The single effect type lithium bromide refrigerating machine primarily comprises a generator, a condenser, an evaporator, an absorber, a solution pump, a solvent pump, a vacuum pump, a heat exchanger and a condensate water heat exchanger. A heater communicating to a driving heat sourceis arranged in the generator, and water vapor obtained by heating an intermediate lithium bromide solution in the generator enters the adjacent communicated condenser; a cooler communicating to a cooling water source is arranged in the condenser, the water vapor entering the condenser is cooled to a refrigerant solution, and the refrigerant solution forms a concentrated lithium bromide solution after water is evaporated; the solvent solution which is throttled enters a liquid collecting tank of the evaporator connected; the refrigerant solution in the liquid collecting tank of the evaporatoris pumped up by means of a connected refrigerant pump to be uniformly sprayed to a connected cold water heat exchange tube in the evaporator to be evaporated to low pressure water vapor and enter theabsorber which is arranged adjacently. The single effect type lithium bromide refrigerating machine provided by the invention has the characteristics of being high in reliability, good in energy saving property, capable of replacing an electric refrigerating machine and the like.