A solar water heater valve comprises a valve body, wherein left and right water pipes and a right water inlet and outlet pipe are respectively arranged on the two left and right sides of the valve body. The left inlet and outlet water pipes and the right inlet and outlet water pipes respectively communicate with the mixing water chamber through a mixing valve. The mixing water chamber is communicated with the inner end of the drainage passage, and the water outlet of the drainage passage is located at the front of the valve body. The right inlet and outlet water pipes are connected with the front end of the right rear passage, the rear end of the right rear passage is connected with the right end of the upper water passage by the normally closed electromagnetic valve, the middle part of the water collecting passage is provided with a hydraulic cylinder, The lower end of the rear part of the opening and closing handle of the mixing valve cooperates with the left end of the upper water passage and the rear end of the left rear passage. The front left of the left rear channel is connected with the left water inlet and outlet water pipe, and the right water inlet and outlet pipe is connected with the pilot control cavity of the pilot valve through the right front water pipe. On the front right through the water pipe is equipped with a normally closed solenoid valve. The purpose of the utility model is to provide a solar water heater valve which has the advantages of simple installation, convenient use and energy saving.