Abstract:  Ocean environmental conditions are the main factors that affect the motion of ship body. In order to properly predict the ship motion according to actual environmental conditions, the operators should get the knowledge about the fundamental rules of ocean environmental conditions affecting the ship motion. Using the real monitoring data of HYSY112 floating production, storage and offloading system (FPSO) operating in CFD oil field of Bohai, applying the maximum entropy principle and statistical analysis technique as data processing tools, the relevance results including the joint distribution and combination rules of wind, wave and current are obtained. This research can offer theoretical support for the FPSO production decision.