Internal grinding head and grinder composing same

The utility model provides an internal grinding head and a grinder composing the same. The internal grinding head comprises an internal grinding head body, grinding elements and a grinding wheel connecting a long shaft. A plurality of first grooves which extend along the axial direction of the internal grinding head body are arranged along the circumference of the internal grinding head body; the grinding elements are detachably arranged in the first grooves and extend to the external ends of the first grooves along the external end of the axial direction of the internal grinding head body; a first end of the grinding wheel connecting the long shaft is connected with the internal grinding head body, and the second end of the grinding wheel connecting the long shaft is used for connecting a main shaft of an internal grinding tool of the grinder. The grinding elements of the same size matching the utilization of the internal grinding head bodies with different sizes are convenient to disassemble; when grinding