The invention relates to the technical field of application of solar energy, in particular to a solar water heater. The solar water heater comprises a solar water heater, and a solar power generationsystem arranged on the solar water heater; the solar power generation system comprises a solar panel, a solar controller, an accumulator and an inverter; and the solar water heater is provided with atemperature sensor and a water level sensor. When the temperature of water reaches a set value, the solar power generation system is closed, so that the temperature of the water can be controlled at aproper temperature, the use demands of people are met, and the energy is saved; an alarm device, arranged on the water heater, induces the temperature change; when the temperature of the water is lower or higher, an alarm is given, and the solar power generation system is automatically cut off to prevent injury of people caused by higher temperature of the water; and the water level sensor is arranged in a water tank of the solar water heater for detecting the storage quantity of the water in the solar water tank to conveniently adjust the water storage quantity in the water tank.