Abstract: In order to reduce the difficulty and improve accuracy of discharge measurement when using SVR handheld wave current meter in mountain stream, the velocity coefficient calibration of SVR was analyzed on the basis of observation data under high, medium and low water levels in Xiquan hydrology station of Heili River during two years. Then, we explored influence factors and calibration process of the velocity coefficient by principal component analysis, correlation analysis and accuracy evaluation in this paper. The results showed that. ① he correlation between water depth and the velocity coefficient of SVR was strong, however the correlation between wind power and the velocity coefficient of SVR was weak in Xiquan hydrology station. Therefore, the velocity coefficient calibration should be carried out under different water levels. ② The velocity coefficients of SVR were 0.85, 0.80 and 0.77 under high, medium and low water levels respectively in Xiquan hydrology station, which was accurate and reliable according to the accuracy evaluation results. This paper could provide theoretical support for selection and calibration of SVR velocity coefficient in other hydrology stations.