Temperature compensation and pressure correction methods are presented to improve the measurement accuracy of pressure and temperature in the rotor cavity. Aimed at the problem of large temperature measurement error caused by no electromotive force produced in the ordinary wires of the slip ring during rotor experiment，the temperature compensation method is used to add the electromotive force calculated from the temperature difference into the output electromotive force. Then, the true temperature of the measurement point can be calculated according to the relationship of the thermocouple between electromotive force and temperature. Aimed at the problem of the measurement error of the sensor installed in the low radius location caused by the piping effect of the air column in the tube in the rotating state of rotor cavity，the pressure correction method is presented. The air column in the tube is divided into several sections and the temperature of each section is regarded as constant. Then the correction formula is deduced. Experiments have been conducted to verify the application effects of the proposed temperature compensation and pressure correction methods. The results show that the measurement error after the compensation of temperature measured by the thermocouple is less than 1% and the measurement error of pressure after correction is less than 0.8%, and the correction effect of pressure is more obvious under high rotation speed. The corrected temperature and pressure accuracy meet the actual measurement requirements of aero?engine rotor cavity, providing important technical support for the life assessment of the rotor of aero?engines.