The invention provides a production process of a can body of a three-piece-type metal zip-top can. The production process comprises the following steps: film coating: in-can paint and out-can paint prepared in advance are applied to a carrier film respectively through a coating machine; pre-baking and attachment of protective films: coatings and the carrier film are put into an oven to be pre-baked; film pressing: the coatings are transferred to a metal plate in a manner of film pressing by a roller; can manufacturing after curing: the can is manufactured after the coatings are cured through thermosetting or ultraviolet curing. The manner that the in-can paint and the out-can paint are applied to the film through the coating machine is adopted, on one hand, the uniformity of the thicknesses of the coatings can be guaranteed, on the other hand, solvents in the coatings can be sufficiently and effectively recovered through the oven on a coating line, the operation safety and the environment safety are both guaranteed, the carrier film on the coatings can serve as a protective layer to effectively protect the in-can paint coating and the out-can paint coating on the plate used for manufacturing the can body, cross contamination is prevented, and possible food safety problems are solved.