Large-drift-diameter oil passing valve

The large-drift-diameter oil passing valve comprises an oil conveying pipeline and a piston cylinder, and a flap valve is hinged to the oil conveying pipeline; a connecting rod is arranged between the piston cylinder and the flap valve, so that the flap valve is linked with the piston; the oil inlet end of the oil conveying pipeline is communicated with a cavity on one side of a piston in the piston cylinder, an oil passing bypass is arranged on a cavity on the other side of the piston, and a control valve is connected to the oil passing bypass so that the pressure difference on the two sides of the piston can be changed to drive the flap valve to rotate. According to the lever principle, the internal space is greatly reduced, the weight can be effectively reduced, and the working efficiency is improved; the pilot self-locking type electromagnetic oil passing valve is formed by adopting the self-locking valve, the pilot part is controlled to be switched on and switched off through the small-size self-locking