Abstract: In order to explore the factors affecting the test accuracy of eddy current sensor, the calibration experimental of eddy current sensors were designed and conducted based on the characteristics of eddy current sensor. The experimental results show that the calibrated eddy current sensor can maintain high test accuracy even when applied to composite end faces containing both discontinuous and continuous surfaces. The influence of installation depth, rotational speed and coating on the performance of eddy current sensor was further analyzed. It was found that as the installation depth increases, the range of eddy current sensors increases but the accuracy decreases. The influence of rotational speed on their performance is relatively small, the non-ferromagnetic coating will lead to a decrease in the sensor range. The research provides a theoretical basis and solution for the calibration method and influence factor analysis of eddy current sensor.