Filter and filtering method of oil curtain sealing system of graphite processing

The invention relates to a filter and a filtering method of an oil sealing system of graphite processing. The filtering method uses a coarse (first stage) filter and a fine (second stage) filter for filtration, and in particular the two stages of filters can use filtering nets which can be repeatedly used, wherein the first stage filter uses the work mode that at least two cylindrical circulationfilters (2) are arranged in parallel and simultaneously work. The first stage filter mainly comprises a filtration flow-dividing pipeline device (1), at least two cylindrical circulation filters (2) and a coarse filter control system to be suitable for work flows of different graphite sealing oil curtain columns, i.e. a corresponding number of cylindrical circulation filters can be started for parallel work according to the actual work flow, and the assistant works of periodical maintenance, cleaning or filtration core replacement, and the like of the filters can be flexibly and conveniently carried out without influe