A physical model test is carried out to study the stability of a new type of seawall called grouting and masonry armor.The development process of the instability of the grouting and masonry armor is studied under wave action.Research shows that the stability of the grouting and masonry armor decreases with the increase of the breaking wave parameters and increases with the increase of the opening rate.Similarly,the setting of the suppression layer is conducive to increasing the stability of the grouting and masonry armor.Based on the previous research results,the formulas for calculating the stability thickness of the grouting and masonry armor with different opening rates were given.