Water curtain type external wall energy saving system

The utility model discloses a water curtain type external wall energy saving system, comprising a unit water curtain external wall, a water inlet header pipe, a water returning header pipe, a distributive pipe, a first temperature controlled switch, a second temperature controlled switch, a water storage tank, a heat recovery device, a water returning pipe after heat exchanging, a tap water pipe and a clean hot water supply pipe; the unit water curtain external wall receives the solar radiation; the temperatures of the water inlet header pipe and the water outlet header pipe are induced through the first temperature controlled switch and the second temperature controlled switch; when the temperature reaches the setting condition, the first temperature controlled switch and the second temperature controlled switch are opened; the water in the unit water curtain external wall is discharged through the water returning header pipe; and the water storage tank replenishes new water to the unit water curtain external wall through the water inlet header pipe. The water in the unit water curtain external wall has high-efficiency heat storage capacity; the heat on the surfaces of the buildings can be taken away through the circular flow of the water so as to achieve the purpose of reducing the building energy consumption. In addition, the low-position heat stored in the can be recycled through the heat recovery device; and clean hot water can be prepared to be used on buildings.