Pinpointing hole center is crucial for machining shaft hole of large-scale workpiece. In order to improve the precision and efficiency of workpiece machined, an approximation hole center positioning method is proposed by rotating laser displacement sensor without angular coordinate. Laser displacement sensor is installed on the rotatable spindle, and the rotatable spindle is placed randomly at a different position around hole center. Spindle is moved along two directions respectively, which are mutually perpendicular and both perpendicular to spindle on machine tool, resceltin in the alteration of sensor data. With the application of the approximant positioning method of hole center, relative coordinate of hole center to machine tool can be obtained quickly and accurately, which could accurately guide the subsequent machining. The experimental results show that this method can be used to improve the accuracy and efficiency of hole center positioning.