Rainwater collecting device for green and energy-saving building

The utility model discloses a rainwater collecting device for a green and energy-saving building. One side of the upper part of the building is connected with a water inlet tank; the inner side wall of the water inlet tank is fixedly connected with a fixed plate; a supporting plate is hinged to the bottom of the fixing plate. A water storage tank is placed at the upper part of the ground; a supporting plate is arranged in a water inlet tank; the tension spring is matched with the fixed plate; certain rainwater is stored in the water inlet tank; the supporting plate rotates downwards through the gravitational potential energy of rainwater; gravitational potential energy of rainwater impacts the direct-current generator through the drainage pipe to generate power; the electric quantity is stored in the storage battery; rainwater enters the water storage tank after being filtered by the filter screen, is pumped into the stainless steel tank body through the submersible pump to be disinfected and sterilized, can