Internal-cooling combined ring rolling core shaft

The utility model provides an internal-cooling combined ring rolling core shaft. The internal-cooling combined ring rolling core shaft comprises a connecting base, a core shaft, a core shaft fixing base, a pressing sleeve and a pressing cover, wherein a circular bulge is arranged on the right side of the outer wall of the core shaft; a circular concave table is arranged on the right side of the inner wall of the core shaft fixing base; the core shaft fixing base is sleeved on the core shaft through the circular concave table and the core shaft fixing base and the core shaft are put inside a circular groove on the left side of the inner wall of the connecting base; a step-shaped circular platform is arranged on the outer wall of the core shaft fixing base; a circular bulge is formed on the left side of the inner wall of the pressing sleeve; the pressing sleeve is sleeved on the core shaft fixing base through the circular bulge; and the pressing cover is sleeved on the pressing sleeve and tightly fixed on the o