The invention provides a high-pressure insulating water tube. The high-pressure insulating water tube is used for cooling circulation between high-voltage potential and low-voltage potential of electrical equipment in ultra-high and extra-high electric power system, and is characterized by comprising a water tube and an insulating jacket, wherein metal flanges are respectively arranged at two ends of the insulating jacket; and an insulating layer is arranged between the insulating jacket and the water tube. Compared with the prior art, the high-pressure insulating water tube is provided with the insulating jacket, solves the problem that the water tube is easy to age when used in an outdoor environment, and has an excellent insulating structure so that insulating of the pure-water-cooled tube between high potential and low potential is implemented; and moreover, owing to the design of an equipotential electrode, inner field intensity distribution of pure water in the tube is improved effectively.