The invention provides a low-phosphorous corrosion and scale inhibitor composition. The low-phosphorous corrosion and scale inhibitor composition contains a polymer A, a polymer B, an organic phosphoric compound, phosphorous-free organic acid and/or phosphorous-free organic acid salt and water-soluble inorganic zinc salt. The polymer A is a copolymer of maleic anhydride and allyloxy polyethyoxyl sulfonate, and the polymer B is a phosphorus-free corrosion inhibition polymer. The weight ratio of the polymer A to the polymer B to the organic phosphoric compound to the phosphorous-free organic acid and/or the phosphorous-free organic acid salt to the water-soluble inorganic zinc salt is 1:(0.25-5):(0.08-1.67):(0.025-1):(0.05-1.26). The invention provides a low-phosphorous corrosion and scale inhibitor and application thereof. The low-phosphorous corrosion and scale inhibitor composition effectively reduces the using amount of a corrosion inhibitor, and the cost is greatly saved.