To set up a solid mapping relation between the internal structure of a radiator and its heat dissipation performance to enhance the system’s performance in some bad working conditions,such as in an overloaded or hightemperature environment,a redesign method based on parametersensitivity analysis is introduced here.According to the theoretical descriptions on the heattransfer process given by forcedconvection heat transfer theory,a mathematic model is built to weigh the significance of the radiator’s design parameters to the system’s heat dissipation performance.A sensitivity factor is derived by examining the effect of the variation in each parameter to the output of the system which quantitatively describing the range of the parameter’s influence to the system’s performance.The new design method is expected to be a reference for radiator design under certain circumstance.