To improve the accuracy of the extrapolated V_S30 values of boreholes on engineering sites with shallow overburden, this paper selects certain borehole data from KiK-net database for research. The correlation coefficient matrix was adopted to test the collinearity of parameters, and three parameters that can reflect the characteristics of borehole profiles were determined. Through the optimized subset method, the relationship functions between the residuals of V_S30 estimated by bottom constant velocity (BCV) model and the three selected parameters were established. On the basis of three feature selecting methods including adjusted R², Bayesian information criterion, and k-fold cross-validation, the optimal function was proposed. According to the distribution of mean and standard deviation of residuals between predicted and observed V_S30 values, a correction function of BCV model was proposed. Results show that the extrapolation model of V_S30 could improve the prediction accuracy of BCV model, and it was applicable in Xinjiang region. The method proposed in this paper can provide reference for developing empirical models for estimating V_S30 in other regions of China.