The invention relates to an internal expansion plugging device for a
cam shaft hole. The internal expansion plugging device for the
cam shaft hole comprises a pull rod, a rear end inner sleeve, inner sleeves, a front end inner sleeve, outer sleeves, O-shaped rings, a pin, a
handle and springs, wherein a boss structure with the increased outer
diameter is arranged at one end of the pull rod, the other end of the pull rod is movably connected with the
handle through the pin, a
cam structure is arranged at the position of connection between the
handle and the pull rod, and the pull rod penetrates through the rear end inner sleeve, the first O-shaped ring, the first outer sleeve, the second O-shaped ring, the first inner sleeve, the third O-shaped ring, the second outer sleeve, the fourth O-shaped ring and the front end inner sleeve in sequence. According to the internal expansion plugging device for the cam shaft hole, the purpose of plugging an oil hole formed in the multi-gear cam shaft hole can be effectively achieved, and plugging is reliable.