The invention discloses a collector of a solar water heater. The collector of the solar water heater comprises a transparent vacuum outer tube and a heat collection inner tube, the heat collection inner tube is inserted into the vacuum outer tube, and the two ends of the heat collection inner tube are connected with the outer wall of the vacuum outer tube in a sealing mode; the heat collection inner tube comprises a heat conduction outer tube, a heat storage layer and a heat conduction inner tube, the heat storage layer (2) is arranged between the heat conduction outer tube and the heat conduction inner tube, and the two ends of the hear storage layer are connected with the heat conduction outer tube and the heat conduction inner tube in a sealing mode; the materials of the heat storage layer are phase-change materials, and the phase-change materials are mixtures of carbon powder, coupling agents, polyethylene wax, and paraffin. The collector of the solar water heater has the advantages that the structure is simple, on one hand, collected solar energy is converted into heat energy, and the heat energy are fully stored in the heat storage layer (2); on the other hand, the preparation is simple, the cost is low, the poisonless and harmless properties are achieved, and the popularization and the application are facilitated.