To address the issue of unclear identification of key control factors affecting the service life of pile supported wharves, we systematically investigate the relationship between the damage of major components and relevant influencing factors.On the basis of grey relational analysis and the BP neural network method, we select 37 in-service pile supported wharves as research objects to analyze the induced relationships between component damage degree and three categories of control factors：time, environment, and materials.The results show that, at the specific factor level, the grey relational grades of service life, annual average precipitation, annual average temperature, and chloride ion concentration all exceed 0.62, indicating a strong correlation with component damage.At the overall factor level, environmental factors have the most significant impact on component damage, with a weight of 66%, followed by material factors (22%) and time factors (12%).