A calibration method for a rotary scanning system is proposed based on two-dimensional profile data. Firstly, key features oftwo-dimensional profile data collected by each sensor are extracted, and the accurate calibrations for relative poses of multiple sensors are achieved by establishing the matching relationship of the obtained features. Secondly, initial solution of the rotating axis is estimated based on the geometric constraint among the laser plane, target, and rotating axis. Meanwhile, the target optimization function is established based on the target radius size, and the precise pose of the rotating axis can be solved iteratively. Experimental results show that the measurement accuracy reaches 0.08 mm, and the measurement time is 20 s. The proposed method can replace the manual detection, achieve on-line measurement of wheel size, and be applied to 3D measurements for other large rotators.