Abstract: In order to overconce the buildings exterior wall insulations defects such as energy-saving structure is not precise,energy-saving rate is low and easy shedding cracking,the methods of case studies,data analysis and theoretical interpretation are used to identify the crux of the problem: the energy-saving design is confined to solid thermal conductivity;although the release is noted in crack control mechanism,yet still resistance mainly;the thermal bridge treatment is not completely,and so on.A number of energy-saving improvements on the construction of the external walls is proposed: To development of radiation-based energy-saving heat exchanger that can restrict heat radiation;giving full play to air cavity in the winter insulation performance and the summer thermal exchange and flow characteristics;setting up small seam of deformation,creating release in crack control mechanism;thermal bridge treatment should be perfected,and attention should be paid to the improvement on connectors material and so on.The exterior energy-saving structure still need further improvements;bold innovations and care are necessary.