A coastal severe saline-alkali soil improvement and vegetation construction system consists of four parts of content, respectively a soil improvement part, a saline-alkaline tolerant plant resource utilization and planting technology part, an irrigation and drainage mating system part, and a part for managing saline-alkaline soil improvement and operation by adopting an automated information technology. A whole set of complete operation system is formed for performing improvement and vegetation construction on saline-alkaline soil from the four parts, thereby providing a feasible high-efficiency method for saline-alkaline soil improvement of a coastal region.