The invention discloses a strong disinfectant, which is prepared from the following recipe ingredients in parts by mass: 4 to 6 parts of phosphoric acid, 1 to 2 parts of surfactants, 6 to 8 parts of benzalkonium bromide, 5 to 7 parts of iodine, 7 to 9 parts of alkyl polyglycoside, 6 to 7 parts of quaternary ammonium salt, 4 to 8 parts of potassium iodide, 6 to 10 parts of octoate type compounds, 10 to 12 parts of oxidized alcohol oxirane and epoxypropane copolymers, 6 to 8 parts of octyl aminoethyl and 4 to 6 parts of polysorbitol. The strong disinfectant is suitable to be used in various fields, and has the characteristics that the recipe is scientific; the preparation is convenient; the manufacturing cost is low; and the bactericidal power is strong, and the like.