The invention discloses a water pipe assembly of a novel water heater. According to the connection way of the water pipe assembly, one end of a traditional tee joint is connected with an external cold water source, one end of the traditional tee joint is connected with a first female elbow which is connected with a cold water inlet of the water heater, and another end of the traditional tee joint is connected with a first accessory through a traditional water pipe. One end of the first accessory is connected with a second female elbow, and the second female elbow is connected with a hot water outlet of the water heater. A first connecting pipe and a second connecting pipe of a third accessory are respectively connected with one female elbow, and the two female elbows are connected with water mixing valves. The first accessory, a second accessory, the third accessory, a fourth accessory and a fifth accessory are connected with one another through cold-hot two-layer straight pipes. Hot water flows in the center of the pipeline, and cold water flows on the periphery of the hot water. Heat dissipated from the hot water is completely absorbed by the cold water, and heat losses are avoided. When water flow is temporarily interrupted, water temperature will not decline greatly.