The real-time ocean wave simulation idea is introduced into the study of interface disturbance wave in annular flow to realize the accurate measurement of the liquid film thickness. A model of interface disturbance wave based on three-level ocean wave function is established based on the theoretical analysis and experimental research of the annular flow interface wave. A wavy liquid film thickness measurement sensor with adjustable insertion depth is designed based on direct measurement method. A dynamic calibration method of time-average liquid film thickness based on duty cycle algorithm is proposed. The source of measurement uncertainty of the sensor is analyzed and evaluated, and the system error compensation algorithm is proposed. The sensor is tested and verified on a double closedloop adjustable pressure medium pressure humidity experimental device. Results show that: under the conditions of arbitrary statistical time and arbitrary insertion depth increment, the relative measurement uncertainty of 94. 44% of the experimental points is within 2% when using the three-level ocean wave model. The liquid film thickness is reproduced using the direct measurement method and the measurement accuracy is improved using the system error compensation algorithm.