Measuring tool for measuring inner hole depth of three-pin-axis fork

The utility model relates to a measuring tool for measuring inner hole depth of a three-pin-axis fork, which comprises a guide sleeve, wherein the guide sleeve comprises a top plate and a sleeve chuck which extends downwards along the edge of the top plate; a dial gauge is fixed on the top plate; the lower part of the dial gauge is connected with a gauge extension rod; the gauge extension rod is positioned inside the guide sleeve; the guide sleeve is sheathed outside a measuring rod; one end of the measuring rod contacts the gauge extension rod; and the other end of the measuring rod is positioned outside the guide sleeve. When measuring, the measuring rod is extended into the inner hole of the collation part to obtain a dial gauge reading, and then extended into the inner hole of the three-pin-axis fork to be measured, and the two dial gauge readings are compared to obtain the inner hole depth of the three-pin-axis fork to be measured. The measurement is accurate and quick.