A coordinate measuring machine precision calibration detector comprises a guide pillar, wherein the guide pillar is arranged on a base, a rack guide rail is machined on the obverse side of the guide pillar, a guide groove is machined in the reverse side of the guide pillar, the guide pillar is sleeved with a guide holder, and the obverse side of the guide holder is provided with a square hole. A gear in contact with the rack guide rail is mounted on the guide holder, wherein the gear is used for fine adjustment of the guide holder through a net-shaped hand wheel. A guide stud transversely penetrates through the reverse side of the guide holder, wherein the front end of the guide stud is located in the guide groove, the net-shaped hand wheel is mounted at the rear end of the guide stud, and the guide stud is used for fixing the guide holder to the guide pillar. An angle adjusting seat is further mounted on one side of the guide holder, wherein the angle adjusting seat is provided with a semicircular through groove, and a cuboid-shaped platform and a gauge block fixing device of the platform are fixed above the angle adjusting seat. By means of the coordinate measuring machine precision calibration detector, fine adjustment of a gauge block to any proper height and continuous adjustment of the angle of inclination of the gauge block are realized, the gauge block can be used for measurement in different directions at different angles and heights, the arrangement is simple, the coverage is full, the amount of labor is small, consumed time is short, the measuring result has a small error, and work efficiency is high.