Abstract: For solar thermal photovoltaic combined modules consisting of concentrators and photovoltaic/thermal (PV/T) devices, a theoretical model for photovoltaic-thermal coupling of solar energy flow within the module was established. Under steady-state conditions, the electrical and thermal output performance of the module was calculated using the theoretical model and experimentally verified. The results show that the theoretical calculated photovoltaic efficiency of the module is 13.1%, and its thermal efficiency is 53.0%, while the experimentally measured photovoltaic efficiency is 13.0%, and the thermal efficiency is 52.8%. The close match between theoretical and experimental results demonstrates the high accuracy of the theoretical model. During the study, it was found that the environmental temperature has minimal influence on the module’s thermal efficiency, primarily because the concentrator replaces most of the PV/T devices, thereby reducing the top heat loss area of the PV/T device, and consequently reducing the thermal losses of the module.