The invention discloses a multistage filtering oil filter. A first filtering element is arranged in a casing to divide an accommodating cavity into a filtering cavity at the upper portion and a liquid outlet cavity at the lower portion, a filtering barrel is vertically arranged in the filtering cavity, a filtering screen structure is arranged on a lateral wall of the filtering barrel, a driving mechanism is connected with the filtering barrel and used for driving the filtering barrel to rotate around a rotating shaft of the driving mechanism, a second filtering element is fixed with the filtering barrel and spirally extends along the filtering barrel, the second filtering element is prepared from a foldable filtering material, and a folding line of the second filtering element is distributed in the radial direction of the filtering barrel. The optimally-designed multistage filtering oil filter has optimal and reasonable structure design; during work, the driving mechanism can drive the filtering screen to drive the second filtering element to rotate, the filtering screen can coarsely filtering machine oil and distribute materials at the same time, and the second filtering element can rotate to filter-press the coarsely-filtered machine oil to an oil inlet; the second filtering element is prepared from the foldable filtering material, so that a filtering area is guaranteed, and solid impurities in the machine oil are effectively removed at the same time; thus, filtering efficiency and a filtering effect are greatly improved.