A comprehensive bridge efficiency evaluation system comprising 30 indicators across five levels was intro-duced.Indicator weights were derived using the G1 method and reliability theory.A substantial sample database with 7 100entries was generated via the cubic spline interpolation method.To optimize the Extreme Learning Machines(ELM)performance,the Dung Beetle Optimization(DBO)algorithm was employed,yielding an evaluation model with an average error margin below 2%.An efficiency analysis of a 65-meter steel-composite small box girder bridge yielded an overall ef-ficiency score of 92.34.Detailed scores include:93.37 for safety,95.05 for applicability,92.4 for durability,90.04 for pro-tection,and 88.83 for green economy.These findings illustrate the high comprehensive efficiency of this bridge type,con-sidering investment cost,construction duration,and environmental impact.The proposed methodology and results provide a robust framework for informed investment,design,and construction decisions in bridge engineering.