To optimize the structures and to evaluate the wave loads of a floating platform reasonably, several frequently used methods of evaluating the wave loads are introduced and summarized, these methods have been used in the design of a new type floating platform. The results show that the max values of most RAO curves can avoid the extreme sea conditions, and the design waves from these evaluation methods of wave loads are very different. This study is helpful for structure type design, wave loads and strength evaluation in similar cases.