Improving the sustainability of civil aircraft represents an inevitable trend in modern aviation industry. This paper develops an integrated methodology for aircraft sustainability evaluation and optimization to achieve optimal sustainable metrics for civil aircraft. It employs three modules to represent synthesized sustainable performance, including economic analysis, environmental assessment, and comfortability evaluation. A multidisciplinary optimization framework is established using collaborative optimization algorithms for sustainability-oriented design optimization. The methodology is applied to a narrow-body airliner configuration, which demonstrates concrete improvements in 1.5% noise reduction, 6.3% lower emissions, 0.84% production cost savings, and 8.6% maintenance cost reduction through reasonable design changes. These results validate the effectiveness of the proposed method in supporting sustainable aircraft design, while revealing the intrinsic correlations between aircraft design parameters and sustainability performance through comprehensive metric evaluation and systematic optimization.