Offshore wind power generator shell protection layer

The invention provides an offshore wind power generator shell protection layer. The protection layer is arranged on the outer wall of the power generator shell. The protection layer comprises a casingfor protecting the power generator shell, a coating for preventing corrosion of the casing and a gear box for enabling a rotating part to rotate along with an impeller, wherein the middle of the casing is provided with a hollow rotating part 111 and fixing ends fixedly connected to two ends of the power generator shell; the coating is arranged on the outer wall of the casing; the rotating part and the power generator impeller are in rotating connection through the gear box. The casing with the rotating part is arranged to protect the shell against corrosion, the rotating part is internally provided with a filter device for filtering salt spray and water vapor, the rotating speed of the rotating part changes synchronously with that of the impeller, when the wind speed increases, rapid rotation enables the salt spr