The invention discloses a rotation spraying gun dephosphorizing device for a ladle and belongs to the technical field of pretreatment of molten iron. The rotation spraying gun dephosphorizing device comprises a rotating connector, inner wall abrasion-resistant steel pipes, thrust bearings, a sealing cover, smoke hoods, a powder spraying gun and a mixed gas spraying gun. The spraying hole axes of the powder spraying gun and the mixed gas spraying gun intersect and have an included angle alpha, and the spraying gun axes of the powder spraying gun and the mixed gas spraying gun intersect and havean included angle beta; the powder spraying gun sprays and blows pre-melting dephosphorizing agents in an intrusive mode, and carbon dioxide serves as a carrier gas; and the mixed gas spraying gun sprays and blows mixed gas of oxygen and carbon dioxide; and the powder spraying gun and the mixed gas spraying gun can rotate freely around the centers of tracks under the counterforce of a fluid. Therotation spraying gun dephosphorizing device has the advantages that instead of being driven by external force, the spraying guns can rotate freely only by means of the counterforce of the fluid; a moving dephosphorizing point and a moving fire point can be formed, the slag-iron reaction area is increased, slagging is fast, the interface reaction rate is increased, and the dephosphorizing effect is good; and the positions of the powder spraying gun and the mixed gas spraying gun are exchanged repeatedly, the utilization rate of dephosphorizing slag is high, the treatment time is short, the temperature drop is small, slag consumption is less, and splashing is relieved greatly.