High-strength spline shaft capable of preventing tooth breakage

The utility model discloses a spline shaft with high strength and capable of preventing tooth breakage, which comprises a limiting device, a supporting device, a first protective sleeve shell, a second protective sleeve shell, an inserting hole and an inserting clamping shaft, four groups of inserting clamping shafts are uniformly and equidistantly inserted into the inner end surface of the supporting device in a sliding manner through limiting devices, and inserting holes are formed in the positions, close to the bottoms, of the outer end surfaces of the inserting clamping shafts. By arranging the limiting device, the connecting screw rod can be in threaded connection with the threaded sleeve plate, so that the mounting clamping plate can drive the inserting sliding shaft to limit or separate the four groups of inserting clamping shafts at any time, and the stability of subsequently replacing and limiting the first protective sleeve shell and the second protective sleeve shell is effectively improved; the se