The invention relates to a method for planting impatiens wallerana in a coastal saline-alkali land. The method comprises the following steps of land preparing, soil improving, planting, water controlling and fertilizer adding. The soil improving step comprises the processes that saline-alkali soil is doped with river sand, grass carbon and decomposed cow dung, the soil, the river sand, the grass carbon and the decomposed cow dung are proportioned according to the ratio of 2 to 2 to 1 to 1, the land is ploughed and dug, and the ploughing and digging depth is 20-30 cm, so that the soil is sufficiently mixed with the river sand, the grass carbon and the decomposed cow dung to be uniform, and then the land is leveled; sampling is conducted, the pH value of the soil is determined, when the pH value of the soil is still larger than 8, ferrous sulfate needs to be applied to the soil, ferrous sulfate is mixed with water for spraying according to the amount that when the pH value is decreased by one, 130 g of ferrous sulfate needs to be applied to per square meter of the soil, and when the pH value of the soil is smaller than or equal to 8, ferrous sulfate does not need to be applied. By using the method for planting the impatiens wallerana in the coastal saline-alkali land, the survival rate of the impatiens wallerana can be greatly increased, and the flowering time and the turf grass growing time are shortened; when the method is used for planting the impatiens wallerana, flowering can be achieved after 15 days, the best landscape effect can be achieved after 20 days, and the survival rate reaches 95% or above.