Abstract: A closed pressure atomization spray cooling system with R600a was used to study the heat transfer process of spray cooling. The modeling of droplets impinging on hot surface was built and the moving state was analyzed. The convective heat transfer of liquid film was ignored and Weber number was used to amend the heat transfer convection coefficient between the droplets and the heater surface. Furthermore, the theory of secondary nucleate boiling was referenced to amend empirical correlation of nucleate boiling. Based on the above analysis, empirical correlations of heat transfer coefficient were built by considering the convection and nucleate boiling. By comparing to the correlations and experimental measurements of other researchers, and comparing to different coolants and experimental systems, we found that the errors of the predicted values and the experimental measurements were within 20%. So the empirical correlation can well predict the heat transfer coefficient of closed pressure spray cooling system.