Automatic flower-watering device

The utility model discloses an automatic flower-watering device, which utilizes a hygristor to sense soil humidity; when the soil humidity changes, a resistance value changes correspondingly, and consequently the voltage of a circuit is changed, the voltage is amplified by an amplifying circuit to serve as an input voltage of a comparison circuit to be compared with a standard voltage. The standard voltage is the voltage value corresponding to the standard soil humidity. When the soil humidity is smaller than a stipulated humidity, namely the voltage value is smaller than the standard voltage, the output end is high level, thus driving the circuit and driving a relay to close and open, controlling the solenoid valve to open, and thereby water in a water tank flows into a hose and then flows into a flowerpot to water a plant; furthermore, one end of the hose is fixed around the inner side of the flowerpot and provided with uniform water leaks, thus being more uniform in watering and beneficial to growth of the