The invention belongs to the technical field of plant cultivation, and particularly relates to a potted plant automatic watering device. The potted plant automatic watering device comprises a pot body, a base, a compression spring, a support, a water storage tank and a water pump. The potted plant automatic watering device is characterized in that a pot edge is arranged at the upper end of the potbody, a balance weight is arranged in the base, the pot body is arranged above the base, a guide post is arranged in the middle of the base, the guide post is sleeved with the compression spring, a guide hole which protrudes upwards and is provided with a downward opening is formed in the bottom of the pot body, the guide post and the guide hole are in vertical sliding fit, one end of the compression spring is fixedly connected with the base, and the other end of the compression spring is fixedly connected with the lower end of the pot body. The support comprises a horizontal section and a vertical section, the horizontal section is fixedly connected with the base, an installing plate is arranged at the upper end of the vertical section, a contact switch is arranged on the side, facing the pot edge, of the installing plate, and the contact switch is located over the pot edge. The potted plant automatic watering device in the technical scheme has an automatic watering function, and issimple in structure, low in production cost and easy to popularize.