The invention discloses a heat exchange energy-saving 
system for a 
house building. The heat exchange energy-saving 
system comprises a 
temperature difference induction mechanism and a heat exchange ventilation mechanism which are arranged in a wall body, the heat exchange mechanism comprises a 
heat exchanger, and an outer side ventilation opening is formed in the end, close to the outer side of the wall body, of the 
heat exchanger; an inner side ventilation opening is formed in one end close to the inner side of the wall body, and a flow 
control unit is arranged at the inner side ventilation opening and adjusts the flow passing through the inner side ventilation opening according to the 
temperature difference between the inner side and the outer side of the wall body. The ventilation efficiency inside and outside the house can be controlled according to the 
temperature difference inside and outside the house, when the temperature difference is large, the ventilation efficiency is reduced, the heat 
exchange time is prolonged, external air enters the house after sufficient heat exchange, heat preservation and 
energy conservation of the house are more emphasized when air circulation is guaranteed, and meanwhile the comfort of people is improved; when the temperature difference is small, the 
air exchange efficiency is improved, rapid 
air exchange is carried out, the house can be rapidly ventilated, and fresh 
indoor air is guaranteed.