Abstract: Joints between precast elements are inevitable in prefabricated concrete structures. Joints are the key parts for the structure safety and they also influence the thermal performance of building. In prefabricated concrete wall structure, the joint between wall panels may cause thermal bridge without an appropriate design. By applying infrared camera measurement and ANSYS finite element analysis, the paper analyzed the thermal flow distribution around the typical vertical joints between the precast panels. By applying PTemp steady state heat transfer simulation, the linear thermal transmittances of three typical joints of wall panels were calculated and the condensation risk was analyzed. The results showed that thermal bridge existed around T-shaped joint. To eliminate the thermal bridge effect caused by structure construction exterior insulating was needed for this precast wall structure.