The present invention relates to an ocean buoy using a heat shrinkable synthetic resin member and a manufacturing method thereof. The manufacturing method of the present invention comprises: a hollow main body preparing step of preparing a cylindrical hollow main body which has a predetermined diameter and both ends of which are open； a side cover mounting step of fixing a side cover having a disk shape to each of both end portions of the hollow main body to seal the hollow main body； a stacking step of stacking the heat shrinkable synthetic resin member on the outer surface of a resulting product finishing the side cover mounting step； and a heating step of applying heat to a resulting product finishing the stacking step to shrink the heat shrinkable synthetic resin member, thereby enabling the heat shrinkable synthetic resin member to adhere closely to the hollow main body and an edge portion of the side cover. The ocean buoy using the heat shrinkable synthetic resin member according to the present invention can be used as an ocean buoy which is environmentally friendly by forming the outer surface of the buoy with a polyethylene or polypropylene side cover and the heat shrinkable synthetic resin member, has reinforced durability, water resistance, insulation property and airtightness performance, prevents marine pollution and gives a hygienic function by the main body of the buoy, has further reinforced durability, water resistance, insulation property and airtightness performance of the buoy by the heat shrinkable synthetic resin member, has improved workability by manufacturing the buoy more easily, and obtains cost reduction by lightening weight of the buoy.본 발명은 열수축성 합성수지부재를 이용한 해양용 부표 및 상기 부표 제조방법에 관한 것이다. 상기 부표 제조방법은, 일정 직경을 가지며 양단이 개방된 원통형 중공본체를 준비하는 중공본체준비단계와； 디스크의 형태를 취하는 사이드커버를 상기 중공본체의 양단부에 각각 고정하여 중공본체를 밀폐시키는 사이드커버장착단계와； 열수축성 합성수지부재를 이용해 상기 사이드커버장착단계를 마친 결과물의 외측면에 적층하는 적층단계와； 상기 적층단계를 마친 결과물에 열을 가하여, 열수축성 합성수지부재가 수축하여 중공본체 및 사이드커버의 테두리부에 밀착하게 하는 가열단계를
