It is ascertained that the indicators weight system by the Analytic Hierarchy Process and constructed the model of success-degree evaluation method to execute the comprehensive evaluation for bridge preservation and replacement project based on the existing indicators system of bridge strengthening project with the purpose of success-degree in program evaluation. The success-degree classification of the bridge preservation and replacement project improves the system of post-evaluation for bridge preservation and replacement project through division of great success, success, partial success, most failure and failure. It indicates that the evaluation model is simple to assess and conform to the reality.