Rock nano CT pore calibration method

The invention discloses a rock nano CT pore calibration method. The method comprises the following steps: manufacturing an SEM scanning region calibration belt and a CT scanning region calibration belt; carrying out SEM scanning on the top surface of a rock sample; carrying out CT scanning; calibrating an SEM scanning result pore; calibrating a pore threshold value Th of a CT top surface layer by using a pore calibrated by the SEM; and when the pore threshold value Th of the CT top surface layer, which is calibrated by the SEM, is obtained, calibrating other CT pore spaces by using the Th. According to the pore calibration method, SEM experiment data and a nano CT method are combined together, and the result of the nano CT is further calibrated by using the result of the SEM; and the CT data calibrated by an SEM high-precision picture has a clear pore space, and is the same as an SEM result obtained by a direct observation method.