Bag type filtering device

The utility model discloses a bag filtering device, wherein, a filter (1) comprises a filter shell body (6), a filtering bag, a filter inlet (2), a filter outlet (3) and corresponding pipelines, a branch pipe, namely a bypass pipe (5), of a liquid discharging pipeline (8) is arranged on the liquid discharging pipeline (8) that is arranged outside the filter outlet (3), and a bypass ball valve (4) is arranged on the bypass pipe (5). By adopting the technical proposal, the granules in the tank liquid can be ensured not to be blown up by compressed air, the spot cleaning for replacing the filter can be ensured and the quality of the workpiece can be improved; by improving the device, the operation steps are optimized; the structure is simple, the cost is low and the application scope is wider.