Disclosed are a method and apparatus for automatically measuring water quality and usage of tap water. The method of measuring water quality of tap water includes obtaining, by a control device in the water metering apparatus, water quality data with respect to the large amount of tap water supplied through the distribution pipe using a water quality sensor installed on a particular coupling member among the plurality of coupling members and transmitting, by the control device in the water metering apparatus, the water quality data with respect to the large amount of tap water, which is obtained from the water quality sensor, to an analysis server.