The invention relates to a vacuum heat-collection-pipe water heater. The vacuum heat-collection-pipe water heater comprises a water storage tank, heat collection pipes and transparent pipes. All the transparent pipes are rotationally arranged on a shell of the water storage tank through swivel bearings in a buckled mode and capable of freely rotating around the axes of the transparent pipes correspondingly. Each transparent pipe is divided into an outer layer pipe and an inner layer pipe. The space between each outer layer pipe and the corresponding inner layer pipe is vacuumized. Partition plates are circumferentially fixed to the space between each outer layer pipe and the corresponding inner layer pipe at equal intervals with the axis of the corresponding transparent pipe as the axis. All the partition plates extend in the radial direction of the corresponding transparent pipes. Each transparent pipe is divided into a set of equal vacuum cylinders through the corresponding partition plates. The tops of all the vacuum cylinders are provided with pressure valves. Each pressure valve communicates with the water storage tank through a flow guiding channel. The vacuum heat-collection-pipe water heater has good heat preservation performance, and automatic transposition can be performed when the outer layer pipes are damaged, so that the effect that the heat collection pipes always conduct heating in a sealed and vacuum state is ensured.