The invention discloses a flanged vibrating screen adjustable hole shrinkage mechanism. The flanged vibrating screen adjustable hole shrinkage mechanism comprises a tank, screen plate bodies, a vibration exciter, push plates and movable screen plates. The upper end of the tank is provided with a feed port. The screen plate bodies are arranged in the tank. Each screen plate body comprises a fixed screen plate and one movable screen plate. The fixed screen plates and the movable screen plates are both provided with screen holes. One end of each movable screen plate is rotatably connected with the inner wall of the tank through a connecting part. The push plates are fixed to the other ends of the movable screen plates correspondingly. The push plates are slidably connected with sliding portsformed in the tank. A rotary slot is arranged on the portion, located on one side of each movable screen plate, of the tank. The bottom of the tank is provided with guide grooves. The guide grooves are slidably connected with guide posts fixed to the upper end of a base. Springs are arranged between the tank and the base. The vibration exciter is mounted at the bottom of the tank. The flanged vibrating screen adjustable hole shrinkage mechanism is provided with the tank, the screen plate bodies, the vibration exciter, the push plates and the movable screen plates, and the problems that screenholes of a flanged vibrating screen cannot be adjusted and are low in applicability are solved.