The invention relates to a waterway structure of a milk brewing machine. The waterway structure comprises a water storage tank, one or more first cooling pipe, a thick-film heater and a constant-temperature cabin, wherein a normal-temperature water inlet and a normal-temperature water outlet are formed in the water storage tank; and a second spiral pipe is arranged in each first cooling pipe. Normal-temperature water of the normal-temperature water outlet flows into a first water inlet of each first cooling pipe after being subjected to flow distribution; after first water outlets of all the first cooling pipes are subjected to flow confluence, the normal-temperature water flows into the thick-film heater for heating, and the water is heated to 90-100 DEG C; and the hot water flowing out of an outlet of the thick-film heater flows into the second spiral pipes for water cooling, and after being cooled to the preset temperature, the hot water flows into the constant-temperature cabin. According to the structural design, the cooling effect is improved, rapid heating is achieved, and energy is recycled, so that the energy-saving effect is improved.