To reduce the wave reflection at the front of the wharf and improve the berthing stability of ships，more and more perforated caissons are used in quay wall projects，but there still is a lack of systematic explanation on caisson opening types in relevant codes of practice.Taking the fourth phase project of Dayaowan Port area of Dalian Port as an example，we use the physical model experiment to emphatically analyze the effects of different caisson opening types on wave height reflection coefficients at the front of the wharf under the action of irregular waves.The results show that the wave height reflection coefficient is usually smaller driven by short-period wave than designed wave.The wave attenuation performance of test section is best in designed low water level.The wave cavity of caisson parapets takes less effects on reducing the wave reflection.The wave reflection coefficient is mainly dependent on percentage of opening.