The contradictory problem that “blocking” the solar radiation in summer and “receiving” the solar radiation in winter for buildings thermal design should be considered in hot summer and cold winter zone in China. In this paper, the typical building in hot summer and cold winter zone was analyzed by theoretical deduction, simulation calculation and experiment validation in order to obtain the effect of different envelope design parameters on internal and external surface temperature changes and heat/cold load demand. The results show that when the solar radiation absorption coefficient decreases from 0.9 to 0.3, the external surface temperatures of envelopes are reduced significantly, and the largest declines of the maximum temperature and the average temperature are 20.2 degrees and 6.9 degrees (roofs), respectively, but there is no change of the internal surface temperatures. By reducing the solar radiation absorption coefficient, building cooling load demand in summer can be decreased significantly, and nearly no effect on heating load in winter. The building heating load in winter can be reduced by increasing the thermal resistance of walls and roofs, and the thermal resistance and energy savings are approximately linear, but the effect of the thermal resistance on the building cooling load is less than building heating load, and there are “anti-saving” risks. This study is valuable, and will be helpful to design building envelopes and heat insulation so as to realize energy consumption reduction of the air conditioning in the whole year in hot summer and cold winter zone.