Combining with the open caisson type of a port in Yantai，we apply a 1∶35 wave cross-section physical model to study the wave dissipation effect and wave impact load of open caissons with two column block superstructure and side opening superstructure. The results show that under the same wave condition，the wave attenuation effect of the increase of the opening rate of the caisson is better than that of the double column wave attenuation block. The biggest area of wave pressure of wave and open caissons of double column block upper structure is under the opening，while the biggest area of wave pressure of open caissons of side opening upper structure is near the opening. The wave force of open caisson of double column block superstructure is mainly affected by static water level，while the wave force of open caisson of side opening superstructures is mainly affected by the degree of inundation of wave surface.