Abstract: Multibeam backscatter intensity is easily affected by angular response effects. Under complex substrate conditions, fixed grouping methods often result in reduced correction effectiveness due to mismatches between the grouping scale and substrate variations, which in turn affects the true representation of seafloor substrate spatial distribution. To address this issue, this paper proposes an adaptive correction method for multibeam backscatter residual angular response based on statistical change point detection. This method constructs a proxy signal using ping-averaged backscatter intensity, performs adaptive grouping in substrate change regions through change point detection, and completes residual angular response correction on this basis. Experimental results show that this method can effectively mitigate systematic effects caused by angular response, reduce bright spots near the central beams and splicing traces between groups, and decrease the correlation between backscatter intensity and incidence angle in diffuse reflection areas. Local comparative analysis indicates that the method has good intensity consistency in uniform substrate areas and can better preserve spatial variation features in complex substrate areas. The research results can provide useful reference for refined processing of multibeam backscatter data and seafloor substrate classification.