Cold rolling method of ultrathin precise medium-width tinplate substrate of 0.05-0.1 mm with mirror surface light

The invention discloses a cold rolling method of an ultrathin precise medium-width tinplate substrate of 0.05-0.1 mm with mirror-surface light. Tinplate raw material strip steel with a thickness of 1.8-2.5 mm is rolled to obtain a tinplate substrate with a final thickness (delta) of 0.05-0.1 mm; and the cold rolling method comprises the following steps: the primary rolling includes at most four passes; the total screw-down rate is 75-80%; the rolling force is 300-335 t; the raw material strip steel is finally rolled to reach 0.35 mm; in primary annealing, the annealing insulation temperature is 650-680 DEG C, and the insulation time is 12-14 hours; the secondary rolling includes at least three passes; the strip steel is rolled from the thickness of 0.35 mm to reach the final thickness (delta)+0.005 mm; the total screw-down rate is 75-77%; the rolling force is 190-210 t; the tension is 1.2-1.4 t; in secondary annealing, the degreasing and the wet leveling are omitted; the drawing and straightening are performe