The invention relates to the field of cold rolling unit mechanical equipment, in particular to a cold rolling unit emulsion system moisturized through steam condensate. The cold rolling unit emulsion system comprises an emulsion supply box; cyclic heat pumps and the emulsion supply box form a loop through an emulsion heating loop pipeline, and a heat exchanger communicates with the emulsion heating loop pipeline; a condensate collecting box is installed below the heat exchanger and above the emulsion supply box, and a preheating box of which a box body is located inside the condensate collecting box is welded to the top of the condensate collecting box; the condensate collecting box is connected with the emulsion supply box through a condensate moisturizing pipeline, and a desalted water moisturizing pipeline is further connected to the emulsion supply box; and the condensate moisturizing pipeline and the desalted water moisturizing pipeline are provided with a valve A and a valve B correspondingly, and the valve A and the valve B are opened or closed separately. According to the cold rolling unit emulsion system moisturized through the steam condensate, the structure is simple, the design is ingenious, and the condensate can be efficiently recycled, so that the enterprise production cost is reduced, meanwhile, water resources are saved, and good application prospects are achieved.