The invention provides a solar water heater, which comprises a vacuum heat-collecting tube and a water storage tank, wherein the water storage tank comprises a liner, an interlayer liner, a heat insulation layer and a shell of the water storage tank which are tightly laminated together from inside to outside in turn; and a heat transferring medium is arranged in the vacuum heat-collecting tube and the interlayer liner. The solar water heater is characterized by further comprising a header box connected with the vacuum heat-collecting tune, wherein the two opposite sides of the header box are connected with one end of an upper header tube and one end of a lower header tube respectively, while the other end of the upper header tube and the other end of the lower header tube are connected with the interlayer liner. In the solar water heater provided by the invention, the header tubes arranged on the opposite upper side and lower side of the header box are connected with the interlayer liner between the liner and the heat insulation layer to form a circulating passage on the basis of the conventional in-line pressure-loaded water heater, so the heat transferring medium enters the interlayer liner through the header box and the header tubes to heat the water in the liner, increases the heating area, has the effect of heat insulation, and has better heating and heat insulation effects.