Bridge damage assessment is an important part of highway maintenance management. Based on the research results of previous people, the author organically combines the WBS method, the concept of damage degree and the principle of fuzzy assessment, establishes a comprehensive assessment model of bridge structure damage degree based on WBS, and gives the specific calculation steps for applying the model. The model has clear concepts, systematic and organized, simple calculation, and the conclusions obtained are more in line with engineering reality and facilitate the scientific formulation of engineering decisions.