Disclosed herein is a method of manufacturing a product having a complex shape by using at least one jig and at least one mandrel. The method of manufacturing a product having a complex shape by using at least one jig and at least one mandrel is configured to include: a preparation step of preparing a prepreg sheet and a cylindrical first mandrel around which the prepreg sheet is wound； a first rolling step of forming a first stacking surface by winding the prepreg sheet around the first mandrel； a second mandrel preparation step of locating a second mandrel on the outer circumferential surface of the first stacking surface； a second rolling step of forming a second stacking surface by winding the first stacking surface and the second mandrel with the prepreg sheet； and a core removal step of removing the first mandrel and the second mandrel.
