In order to improve the accuracy,efficiency and maneuverability of risk estimation of highway bridges,a response surface method and the improved Delphi method based framework for risk assessment of highway bridges is proposed.The flowchart of damage risk probability analysis of bridges based on response surface method is presented.The improved Delphi method is proposed to estimate the risk of highway bridges.The results of expert survey are adjusted by an optimization model,then the grade of risk loss is estimated quantificationally using the improved Delphi method.The damage risk assessment under earthquake of a self-anchored suspension bridge is carried out for illustrating the application and efficiency of the proposed methodology.The illustrative example indicates that not only the specific characteristics of the bridge but also the objective existence of uncertainty are considered by the response surface method based bridge damage probability estimation method,structural damage risk probability is calculated quantitatively taking full advantage of existing research results;The improved Delphi method overcomes the deficiencies of the traditional Delphi method,the statistical and computational workload are reduced while the reliability of expert opinions are ensured,so the time required for risk estimation is shortened to improve the efficiency of the risk assessment.