Automatic water injector for wet mop cleaner and water injection method thereof

An automatic water injector for a wet mop cleaner and an operation method thereof which detects the soil level of a mop so as to automatically inject washing water thereto, wherein the water injector has a soil level detector for detecting the soil level of the mop, a controller for controlling the water injection depending on the detected soil level, a water absorber operated under the control of the controller and a water injector operated under the control of the controller. The method includes driving the mop in accordance with a user input, determining if the mop needs to be washed by detecting the soil level of the mop and comparing the detected level with a predetermined standard level, washing the mop if the comparison determines the need for washing the mop and stopping the mop operation according to stop key input. Accordingly, a proper quantity of water corresponding to the soil level of the mop is automatically injected, to thereby provide convenience to users.