The invention discloses an aperture measuring method based on non-contacting type sensor combination, is suitable for measuring the size of the inner
diameter of a workpiece, and relates to the geometric sense measuring field. The method comprises the following steps: first, installing a main shaft of a double-sensor measuring head on a mechanism with the horizontal moving function so as to form a complete set of measuring
system which is arranged in a workpiece to be measured; at measuring time, measuring optical axes of two sensors on the double-sensor measuring head being enabled to be on the same straight line; the double-sensor measuring
head first rotating on a ZOY face, and then horizontally moving on an XOY face, finally the
diameter of an inner hole of the workpiece to be measured is obtained; or, the double-sensor measuring head sequentially rotates on the ZOY face and the XOY face to obtain the
diameter of the inner hole of the workpiece to be measured. When the method is used for measuring the diameter of the inner hole of the workpiece to be measured, only two procedures need operating theoretically, so that measuring efficiency is greatly improved, and a large number of measuring labor hours are saved. Moreover, the non-contacting measuring head is arranged on a lathe, a motion execution mechanism of the lathe is used for enabling the measuring head to rotate or move horizontally, so that on-
machine accurate measuring can be achieved.