A solar heat exchanger and a wall-mounted pressure-bearing tankless solar water heater, including a heat-exchanging water storage tank with multiple cavities inside, and the cavities communicate with each other through holes. One surface is provided with a vacuum interlayer, the other surface is provided with an insulation layer, or a vacuum interlayer is provided on the surrounding surface of the heat exchange water storage tank. The material of the vacuum interlayer panel and the heat exchange water storage tank is polymethyl methacrylate, polycarbonate or polystyrene. Ethylene, the light-receiving surface of the vacuum interlayer panel is a multi-section curved surface with equal arc lengths. There are water inlets and outlets on one side of the heat exchange storage tank, and a reflective film is placed on the back of the heat exchange storage tank. The solar heat exchanger is also equipped with a vacuum interlayer. connected vent valve. The advantages are: high light transmittance, strong impact resistance, heat resistance, weather resistance, acid and alkali resistance, environmental protection and non-toxicity, long service life, can pass through 70% ultraviolet rays, compact structure, high heat exchange efficiency, pressure bearing and water storage , Heat exchange integration, no indoor water storage tank, flexible installation, suitable for balcony and wall installation.