Taught herein is an apparatus for measurement of floating body posture of a person wearing a life jacket, comprising a backpack frame having a plurality of reference points, an image collecting system, and an image processing system; wherein the image collecting system collects image sequence information of the person wearing the life jacket via the reference points; the image processing system processes the image sequence information, so as to obtain the dynamics of a movement of the person and the quasi-static parameters of such movement. The system is capable of reflecting the dynamics of a movement of a body in water and the quasi-static parameters thereof.