Aiming at the problems of dust pollution and damage of battery shell plastic box during storage and transportation, the box needs to be coated after injection molding. However, due to the thin shell of the battery and the serious deformation caused by the protective means of heat shrinkage process, which has a great impact on the product quality, there is an urgent need to design an efficient and convenient protective packaging process of the battery shell. According to the concept of functional modular design, a solution of film wrapping in tray was put forward for the plastic box. Then, for the film wrapping and packaging, an automatic film wrapping process of plastic box was formulated which integrated shaping, film wrapping and material transportation and the mechanical system design of each functional module for film wrapping and packaging was conducted. Finally, the rationality of the process was verified by digital means. The equipment realized the integrated production of shaping, film wrapping and material transportation of various specifications of battery shell plastic boxes, and the efficiency reached 42 s/piece, which was 1.4 times higher than that of manual mode. The structure of the equipment is reasonable. On the premise of ensuring the quality of film wrapping and packaging, the equipment improves the efficiency of film wrapping and packaging, promotes the process of enterprise automation, and provides a solution for automatic film wrapping and packaging of plastic boxes.