Based on the measured data of the surrounding ground settlement in a subway station construction, this paper uses cubic exponential smoothing method to predict the settlement, and the reliability of the method is verified. Research results show the settlement in the existing 14 consecutive days observation data of subway engineering under modeling conditions, compared with time series ARIMA (1,1,1) model, the MSE of the cubic exponential smoothing method is smaller. The method is verified available with the average residual error -0.010 1 and relative error-0.213 9 with better match between predicted value and actual value, ensuring the normal construction and safety of subway station, providing protection for the subsequent project.