Abstract: A water flow rate control device includes a water output device connected to a water supply source for output of water through a water passage defined therein. A water flow rate control unit is mounted in the water output device and configured to close/open the water passage of the water output device and to regulate the water flow rate passing through the water passage of the water output device. A control switch is operated to drive the water flow rate control unit, causing the water flow rate control unit to close/open the water passage of the water output device. A pressure relief control unit includes a spring supported relief valve mounted in the water output device and coupled to the water flow rate control unit to automatically release a high pressure when the water flow rate control unit is driven to close the water passage of the water output device.