The present invention relates to a coated buoy using a cylindrical coating member and a manufacturing method thereof. More specifically, the present invention relates to a coated buoy using a cylindrical coating member and a manufacturing method thereof, the coated buoy which surrounds the body of the Styrofoam buoy to form the surrounded body of the Styrofoam buoy without a joint part by extruding a sheet such that the sheet has a predetermined thickness, winding the extruded sheet on a circular frame several times, heating the extruded sheet wound on the circular frame to form the cylindrical coating member, surrounding the body of a Styrofoam buoy with the cylindrical coating member, and heating and integrally forming the cylindrical coating member surrounded on the body of the Styrofoam buoy. The coated buoy of the present invention includes groove parts and side parts which are formed at both sides of the body, and Styrofoam buoys which are formed at the side parts and to which circular side members are attached. The cylindrical coating member is wound on an outer diameter of the body and is heated to be integrally coated with the Styrofoam buoy and side welding parts are welded to the side members at an inner diameter of the front end of the cylindrical coating member. The cylindrical coating member is formed by thinly extruding the sheet, stretching the extruded sheet, winding the stretched sheet on the circular frame several times, and heating the stretched sheet wound on the circular frame. The cylindrical coating member is formed in a cylindrical shape without the joint part due to welding by extruding a sheet with a thickness of 0.15 to 0.5 mm, stretching the sheet to an elongation ratio of 25 to 48%, winding the stretched sheet on the circular frame 3 to 10 times, heating the stretched sheet wound on the circular frame to the temperature of 150 to 190°C by a heater, and maintaining the heated sheet wound on the circular frame for 250 to 350 seconds.본 발명은
