After sealing the two ends of tinplate cans, the outer surface of the sealing line made of tinplate material will cause friction between the cans and damage to the surface coating due to the turbulence in the long-distance transportation. In addition, in the process of empty tank and solid tank sealing, if the sealing wheel surface of the tank sealing machine is not repaired and replaced in time after wear, the coating on the surface of the tank cover will also be damaged. When the above two situations occur, when the tin can through sterilization after the sealing line surface is easy to rust, in order to prevent this phenomenon, need to tinplate sealing line online automatic oiling, forming a protective film, make the sealing line always bright as new, in order to improve the appearance of the product.