Aiming at the low accuracy and slow speed in actual measurement of column, put forward a method which uses geometrical displacement optics precision to measure coaxiality of column in a quick way. The principle of cylinder (cone) coaxiality measurement system is introduced. The principle of least square is used in it. Introduces coaxiality error computational method, error correction, measurement system software structure and module function. The system is validated by experiments. The results indicated that algorithm is concise and easy to realize. The system has the merits of high accuracy, fast speed, non-contact automatic measurement.