Split solar heater water tank

The invention discloses a split solar heater water tank. With the design, the whole system comprises two relatively individual water tanks, wherein the pre-heating water tank is responsible for utilizing the solar energy to heat water in advance, the constant-temperature water tank is responsible for keeping the set temperature of the water, hot water in the pre-heating water tank can surely enter the constant-temperature water tank under the external water pressure via a water pipe and a gas pipe, and the stability of the water temperature of a water outlet pipe is ensured.