Abstract: The treatment of thermal bridges blocking up of ultra-low energy consumption building caused by curtain wall components has often been overlooked. The impact of these thermal bridges on the energy consumption of the building should not be underestimated. At present, the thermal blocking-up method of these penetrations is variety in different projects, and their impact on energy consumption of the entire building has not been researched. Therefore, combining two project examples in the cold climate zone B, the thermal bridge simulation software and energy consumption calculation software were used to analyze the thermal bridge effect of such joints and the impact on building energy consumption. It is concluded that compared with the tradition design method, the design of thermal bridge blocking-up joint should select thicker insulation materials, smaller size of the increased steel material sections, and shorter steel materials in the insulation layer, so as to help reduce thermal bridge coefficient.