The invention discloses a controllable-temperature solar water heater comprising a water tank, a solar heat collector and a temperature sensor. An inlet and an outlet of the solar heat collector are connected with the water tank through pipes so as to form a circulating pipeline. The temperature sensor is arranged on the water tank. The circulating pipeline is provided with a pipeline on-off device that is connected with the temperature sensor on the water tank. The water heater simple in structure is capable of preventing over-high temperature of water so as to guarantee service life of a liner thereof and service lives of hot water supply pipes and valves, protect safety of users in use of hot water and prevent the users from being scalded by hot water.