The invention relates to a papermaking device, in particular to a screening drum of a papermaking machine. According to the technical scheme, the screening drum of the papermaking machine comprises a lower flange, an upper flange, flange discs located between the lower flange and the upper flange and guiding screening bars with screening space. Arc inserting grooves which are used for guiding screening bar to insert and formed in the same direction are evenly distributed on the flange discs; the guiding screening bars comprise inserting ends connected with the inserting grooves in an inserted mode and guiding ends, the inserting ends are arc bodies, the guiding ends are slant surfaces, the highest points of the slant surfaces are joined with the arc bodies through arc join surfaces, and the lowest points of the slant surfaces are joined with the arc bodies through connecting surfaces, wherein first included angles exist between the connecting surfaces and the slant surfaces, second included angles exist between the connecting surfaces and the arc bodies, the second included angles are larger than the first included angles, and confluence areas for collecting and filtering are formed at the join portion of the second included angles and the arc bodies. According to the technical scheme, the screening drum of the papermaking machine is large in filtering throughput, capable of shortening filtering time and reducing the production cost and low in maintenance cost.