Precise security filter

The utility model discloses a precision security filter which comprises a cylinder body, a filter element, a supporting pipe and a placing plate, the top of the cylinder body is connected with a cylinder cover through a hinge assembly, the cylinder body is provided with a water inlet, a water outlet and a drain outlet, and the water inlet and the water outlet are respectively provided with a pressure gauge; a placing plate is arranged in the cylinder body; a plurality of groups of circular holes are formed in the placing plate; two groups of sliding grooves are symmetrically and fixedly connected to the lower part of the placing plate and are positioned on two sides of the circular hole; sliding holes are formed in the containing plate, sliding plates are arranged on the two sides of the supporting pipe, a moving plate is arranged on the supporting pipe, meshing teeth are arranged on the moving plate at a certain distance, the meshing teeth are connected with a gear in a meshed mode, and one end of the gear i