Filter device and filtering method

The invention discloses a filter device and a filtering method, relates to the technical field of filtering separation, and is used for solving the problems that in the prior art, a filtering effect is poor and even a filter cannot work due to the fact that a filtering hole channel of a filter cake formed on a filter disc is blocked. The filter device comprises a hollow rotating main shaft, a hollow scraper shaft, and a hollow water jet cutter shaft; scrapers are arranged on the hollow scraper shaft, the scrapers and the porous material filtering disc are arranged at intervals, and each scraper is arranged in the radius direction of the porous material filtering disc; the hollow scraper shaft is used for removing a filter cake layer accumulated on the porous material filter disc when the porous material filter disc rotates horizontally; the hollow water jet cutter shaft is parallel to the hollow scraper shaft and the hollow rotating main shaft; and water jet cutters are arranged on the hollow water jet cutter