The invention discloses a solar photovoltaic photothermal integrated device for seawater desalination. A photovoltaic panel is connected with a seawater delivery pump, a heat transfer oil delivery pump, a vacuum pump and a control system to supply power, and the control system is used for controlling switches of the pumps. A low-temperature heat transfer oil tank, the heat transfer oil delivery pump, a flat plate heat collector, a paraboloidal condenser, a high-temperature heat transfer oil tank, a high-temperature seawater evaporation chamber and a hot oil pipe of a high-temperature seawaterpreheating tank form a heat transfer oil circulation system. A low-temperature seawater preheating tank is connected to the high-temperature seawater evaporation chamber through the seawater deliverypump, a medium-temperature seawater preheating tank and the high-temperature seawater preheating tank. The bottom of the high-temperature seawater evaporation chamber is connected to a concentrated seawater pipe, and the side wall of the high-temperature seawater evaporation chamber is connected with a steam pipe. The concentrated seawater pipe passes around the low-temperature seawater preheating tank to extend out, the stem pipe passes around the medium-temperature seawater preheating tank to be connected to a condensate pipe and then passes around the low-temperature seawater preheating tank to be connected to a fresh water collector, and the vacuum pump is mounted on the fresh water collector. Solar energy is used for providing electric energy and heat of heat transfer oil to realize a self-sufficient operation mode.