The invention relates to the field of building, in particular to a lifting screw mechanism for a sandstone separator. The lifting screw mechanism comprises a screw machine body and a base, wherein a driving mechanism is arranged at the right end of the screw machine body; a feeding hopper is arranged at the left end of the upper side of the screw machine body; a discharging pipe is arranged at theright end of the lower side of the screw machine body; a mounting base is arranged at the left end of the upper side of the base and is provided with a first telescopic adjusting mechanism; a first connecting seat is arranged at the upper end of the first telescopic adjusting mechanism; the first telescopic adjusting mechanism is connected with the screw machine body through the first connectingseat; the right end of the upper side of the base is also provided with a mounting base; the mounting base is provided with a second telescopic adjusting mechanism; a second connecting seat is arranged at the upper end of the second telescopic adjusting mechanism; sliding rails are arranged at the right part of the lower side of the screw machine body; and the second connecting seat is arranged onthe sliding rails. By adopting structural arrangement of the device, the adjustment of inclined angle and the height of the machine body is realized, different use demands are met, and high practicality is realized.