Microwave-based rotor and stator axial clearance online measurement method and device

The invention belongs to the field of non-contact distance measurement, and aims to realize non-contact real-time on-line accurate measurement of an axial clearance of a rotor and a stator of an aero-engine under a space limited condition. Therefore, the technical scheme adopted by the invention is as follows: the microwave-based rotor and stator axial clearance online measurement device is composed of a microwave signal generation module, a signal power amplification module, a signal receiving and mixing module, a signal conditioning and acquisition module, a circulator and a microwave sensor, and a carrier signal generated by the microwave signal generation module enters a first port of the circulator after being amplified by the signal power amplification module and is output from a second port of the circulator; and the second port of the circulator is connected with the microwave sensor, and the microwave sensor transmits a carrier signal to the axial end surface of the measured rotor, receives a carrier