This paper studies the muddy seabed liquefaction mass erosion and the transportation of concentrated benthic suspension layer caused by wave and seabed corresponding effect.We apply de Wit liquefaction conditions and calculation method,combine the method with local characteristics of wave effect and sediment transport in the Lianyungang coast,and calculate the liquefied depth of the muddy seabed under different wave condition.We also calculate the velocity of liquefied layers further considering the reduction effect on velocity induced by suspended sediment concentration.The results show that the muddy seabed may have substantial liquefaction depth under wind-wave condition,however the depth of movable liquefaction layer is not obvious.Because of the high suspended sediment concentration,large sediment transport can still be formed in the wave-induced liquefaction layer and the channel sudden siltation with a certain scale in high windy day can occur.The results can provide new ideas for seabed stability analysis and sediment transport calculation.