The embodiment of the invention discloses a support structure of a purifier filter bag. The technical problem that in the prior art, according to the technical scheme that the filter bag is wound around a grid-shaped support, fixed on the grid-shaped support and then placed into a purifier for filtering, when the purifier works, wind resistance is large due to the grid-shaped plate structure during wind entering, so that noise is high when the purifier works is solved. According to the embodiment of the support structure, at least two transverse rods are arranged in an outer frame of a grid support, and hollow positions are formed between the outer frame and the transverse rods as well as between the transverse rods; the section of each transverse rod is of a triangle structure; at least one sub-rod is arranged at each hollow position and is perpendicular to the transverse rods, grooves are formed in the sub-rods, and vertical rods are inserted into the sub-rods and used for expanding the filter bag which is arranged below the grid support.