The invention relates to the technical field of household greening equipment, and discloses an automatic watering device for household green plant maintenance, comprising a base box, the inside of the base box is slidably connected with a sealing piston, and the inside of the sealing piston is provided with a capillary damping hole , the capillary damping hole is used to communicate with the upper and lower end chambers of the sealing piston, the diameter of the capillary damping hole is capillary level, the bottom end of the sealing piston is fixedly equipped with a pressure balance spring, and the bottom of the pressure balance spring The end is fixedly connected to the inner bottom of the base box, and the inner bottom of the base box is located on the left and right sides of the pressure balance spring and is provided with telescopic rods. In the present invention, a sealing piston is arranged in the base box, and a capillary damping hole is arranged in the sealing piston, and water droplets are slowly dripped from the capillary damping hole to the green plants, so that the green plant potting soil is in a moist state, the green plants are not easy to wither, and the single-time The amount of the water tank can be used for a long period of time according to the release speed of the capillary damping hole, so as to keep the green plant pot moist.