The invention discloses a calibrator for cage guide installation, and the calibrator comprises a detecting scale and a calibrating mechanism, wherein the detecting scale comprises a first knife-straight edge, a second knife-straight edge, a third knife-straight edge, a U-shaped frame, a locking plate and a locking screw; the calibrating mechanism comprises a bracket, a transverse adjusting mechanism, a longitudinal adjusting mechanism and a fastening mechanism; and the detecting scale is used for detecting, and the calibrating mechanism is used for adjusting the position of the calibrator. By using the calibrator disclosed by the invention, the verticality, twisting degree and apposition degree of cage guide installation are detected by forming a loop by the knife-straight edges and a cage guide; compared with methods of carrying out artificial observation on line transects by using a scale and carrying out knocking approximation by using a hammer in the prior art, the device has the advantages that a fundamental improvement is achieved, the experience requirements on installation personnel are also greatly reduced, and the calibration on the cage guide can be realized just through operating buttons of the calibrator, therefore, the calibrator has extremely strong practicability, and can be used for dramatically reducing the cost of cage guide installation.