In this paper,the algorithm model based on the calibration principle of on-line oil monitoring viscosity sensor is studied.The goal is to optimize the calibration algorithm of viscosity sensor to further improve the measurement accuracy. Aimed at the poor test accuracy of the viscosity sensor,based on the viscosity measuring mechanism,a data processing algorithm model was proposed to calibrate the viscosity sensor.An experimental test platform was designed and built to measure the fluid viscosity in a large temperature range,and the calibration algorithm was verified.The results show that by using the improved calibration algorithm model to calibrate the viscosity sensor,the measurement accuracy and stability of the sensor are improved,and the average absolute error of viscosity measurement can be controlled within 5%.The designed viscosity sensor has good response and high sensitivity to the change of oil viscosity,which can meet the engineering requirements for online real-time measurement of fluid viscosity.