The invention relates to a vacuum chamber flap valve of a continuous type vacuum film plating line. The flap valve is characterized by comprising a valve port, a valve plate, a main driving shaft, a connecting rod, a pivot shaft, an inclining angle adjusting device and a rotary driving mechanism, wherein the main driving shaft is rotationally supported on the wall surface of a vacuum chamber, the first end of the connecting rod is fixedly connected with the main driving shaft, the second send of the connecting rod extends to the back side of the valve plate, the pivot shaft is used for connecting the valve plate and the second end of the connecting rod, the inclining angle adjusting device consists of at least one pair of ejector pin mechanisms, each ejector pin mechanism comprises a pin hole, a sliding pin, an elastic element and a screw, each pin hole is formed in the second end of the connecting rod, each sliding pin is arranged in each pin hole in a penetrating way, one end, facing the back side of the valve plate, of each sliding pin is provided with each elastic element, the other end of each sliding pin is provided with each screw, then each screw is abutted against each sliding pin, the elastic element at the end of each sliding pin is abutted against the back side of the valve plate, the two ejector pin mechanisms are respectively arranged at the two sides of the pivot shaft in the length direction of the connecting rod, and the rotary driving mechanism is used for driving the main driving shaft to rotate. The flap valve has the advantages that the opening and closing actions are quick, the working is reliable, and the sealing effect is ensured.