Filtering system and filtering method

The invention relates to a filtering system and a filtering method. According to the invention, a filtering unit is provided with at least one filter group comprising a plurality of filters; in the same filter group, a communication pipeline is arranged between a filtrate outlet of each filter and a solid-containing raw oil inlet of each filter in the same group, and a communication valve is arranged on the communication pipeline; a control system comprises an on-line pressure difference monitoring module, a filter control module and a regeneration control module, the on-line pressure difference monitoring module is used for monitoring the pressure difference of an on-line used filter, and the filter control module is used for controlling a single filter to be switched in and out of the filtering system; and a regeneration control module is used for controlling the regeneration process of the filters. The filtering system provided by the invention has the characteristic of effective and continuous operation,