This paper investigates the impact of irregular waves under a 300 000 t tanker collision energy by physical model test and analyzes the main factors’impact on collision velocity including H/T,L/B,T/T0,D.The result indicates that the collision speed is proportional to H/T and T/T0,and is powered to L/B.When T/T0=1,the collision and wave resonates,which causes the greatest velocity.The collision speed when the tanker is ballast is larger than that when it is fully loaded.In another word,the collision speed is negatively correlated with the draft.A formula for the 300 000 t tanker collision energy is proposed and compared to the result by physical model test of Qingdao port oil wharf phase III project and Qingdao Yijia Group oil terminal project,which has better accuracy and can be used for reference for design.