Surface heat transfer coefficient is an important boundary condition for numerical analysis of TC17 titanium alloy quenching. Its accuracy will affect the distribution accuracy of quenching temperature and stress field. Based on the dynamic measured temperature drop curve of deep buried thermocouple, the heat transfer coefficient of TC17 titanium alloy quenched surface is calculated by using the improved concentrated heat capacity method, and the reliability of the results is verified by numerical simulation. The results show that there are three main stages in the process of TC17 titanium alloy water bath quenching: Steam film stage, nucleate boiling stage and convective cooling stage. The surface heat transfer coefficient increases rapidly in the steam film stage and nucleate boiling stage, and then decreases gradually in the convective cooling stage. The surface heat transfer coefficient reaches a peak of 1299 W/(m²·℃) at the 50th s, and the quenching surface temperature is 355 ℃. The calculated results are in good agreement with the measured temperature drop curve, and the average relative error is only 1.4%.