The utility model relates to the technical field of high speed railway dual-block type ballastless track laying and ballasting, in particular to an inner supporting type screw rod adjuster. The inner supporting type screw rod adjuster comprises a cross beam, tray adjusting devices, a vertical adjusting rod and a supporting rod. The tray adjusting devices are arranged at the two ends of the beam respectively and used for adjusting the track gauge. Vertical adjusting threaded holes are formed in the two ends of the cross beam respectively and located between the two tray adjusting devices. External threads matched with the vertical adjusting threaded holes are arranged on the outer circumferential face of the vertical adjusting rod so as to adjust the height of the track. The upper end of the supporting rod is connected with the lower end of the vertical adjusting rod and used for supporting the cross beam. Due to the fact that the inner supporting type screw rod adjuster is located in a track skeleton, the phenomenon that the track skeleton cannot be supported at the preset position when the outside space of the track skeleton is not large enough is avoided, the geometrical shape of the track will not be changed, and position displacement of the track will not occur.