The invention relates to a film pressing mechanism for square products. The film pressing mechanism comprises a frame, a film pressing seat with a middle film pressing groove is arranged on the frame, and limiting plates matched with the film pressing seat are arranged on the film pressing seat and positioned on front and rear sides of the groove respectively. A film sending device, an ejection device and a film pressing device are matched with the film pressing groove of the film pressing seat and arranged on the frame. The film pressing device comprises a pressing block above the film pressing groove, the pressing block is arranged on a pressing lift seat which is connected with a matching block through a pressing connection rod, and the matching block is matched with a pressing crank wheel which is connected with a power driving part. Since the film pressing seat with the middle film pressing groove serves as a product carrier, the limiting plates are arranged on two sides of the groove respectively, and the pressing crank wheel and the connection rod can serve as power parts for reciprocation of the pressing block, a moving range of the pressing block can be limited, excessive pressure can be avoided, and accordingly films and products can be protected from being damaged under pressure.