The invention discloses a high-efficiency solar photo-thermal tower-type electricity generation and seawater desalinization integral system, and in the prior art, a mass of non-renewable energy resources are consumed. The integral system provided by the invention comprises a solar thermal collection system, a heat transfer working substance circulating system, an electricity generating system and a seawater desalinization system, and particularly comprises a heliostat, a localizer, a heat absorber, a heat absorber support tower, a heat transfer working substance loop, a pump, a seawater heater, a steam generator, a steam loop, a turbine generator, a power grid, a cold seawater pipeline, a fresh water pipeline, a strong brine pipeline, multilevel flashing equipment and a flow valve, wherein the heat transfer working substance loop and the steam loop are enclosed, and the loop of the seawater desalinization system for generating freshwater is in an open type. The integral system provided by the invention has the advantages of high-efficiency and rapid heat collection function and stability in production of supplying heat, generating electricity and desalinizing seawater; and compared with conventional energy resources, the solar energy is renewable, environmentally-friendly, cost-free and common.