Abstract: Supercritical-water cooled reactor is above the thermal critical point (22.1 MPa,374℃). The coolant is supercritical water which physical property changes sharply with the change of temperature. The characteristic of heat transfer deterioration of supercritical water is that the wall temperature increases slowly via heat power, which is different from CHF of pressured-water reactors. So, forecasting the cladding wall temperature of the fuel rod for heat transfer deterioration is very important for the safety analysis of SCWR. The paper infers the modified term of acceleration effect based on the boundary layer equations. The paper achieves the fitting of the correlative factor of the modified term by the test data and the semi-empirical relationship is gained. By comparing the test data, the relationship is capable to forecast the wall temperature for normal heat transfer and heat transfer deterioration.