The invention discloses a pneumatic cloth pressing device for a composite production line for cables and electric materials. The pneumatic cloth pressing device comprises pinch rolls located in front of drying cylinders (1) of a dryer and a press roll (2) located above the drying cylinders (1), wherein the pinch rolls comprise an upper pinch roll (3) and a lower pinch roll (4) which are fixed up and down, a roll shaft of the upper pinch roll (3) is fixed in a through hole of a pinch roll slider (31), a roll shaft of the lower pinch roll (4) is fixed on a pinch roll slider fixing seat (32), and a roll shaft of the press roll (2) is fixed in a through hole of a press roll slider (21). The pressure between the pinch rolls and the pressure between the press roll (2) and the corresponding drying cylinder (1) are adjusted, and pressure is applied to a base material in operation through the pressure, so that the thickness uniformity of composite cable and electric material products can be improved. The reject ratio of the products is reduced, and the production cost is saved.