Abstract: Verticality detection of vertical shaft is an important part of shaft deformation monitoring, but the current laser plumb instrument is difficult to meet the needs of deep shaft detection. By modifying the laser pointing instrument, the problem of long distance drop of laser collimation datum in a kilometer deep well is solved. And a shaft verticality detection system based on laser collimation is developed by combining laser receiving device, laser ranging sensor, etc. The key problems of laser spot edge extraction, center location and reference calibration of detection system are studied and solved. The project test shows that the scheme of the detection system is feasible. Compared with the double steel wire method, the detection deviation can be controlled within ±1 cm, and the detection time can be reduced by nearly 50%. So, the system can solve the problem of vertical detection of deep shaft.