Due to irregular metallic components, the envelope of prefabricated buildings forms thermal bridges at the wall junctions, affecting the energy performance. However, until now, the effects of different connectors on the energy performance of prefabricated concrete buildings have not been well explored due to the lack of methods to analyse the heat transfer of the wall with the connectors. To investigate the impact of grouted sleeve and bolt connections on wall heat flows, cooling and heating energy consumption, and the amount of dehumidification and humidification in prefabricated concrete buildings, this study has developed a heat and moisture coupled transfer model using COMSOL software and validated its accuracy through experiments. Then, the equivalent heat transfer coefficient method was proposed to calculate the equivalent heat transfer coefficient of the building wall, combined with the WUFI Plus software, to analyse the annual energy consumption of prefabricated buildings in four typical cities with different climatic conditions in China. The results revealed that the use of both connectors increased the flow of heat in the walls, the consumption of cooling and heating energy and dehumidification and humidification. The routed sleeve connections were more energy efficient for cooling and heating energy consumption than the bolted connections in the four cities. The authors hope that this research can provide a reference for an accurate evaluation of the energy performance of prefabricated concrete buildings using different connectors.