[Purposes] The paper aims to ensure the safety performance of bridges and effectively coordinate the relationships of bridge reinforcement methods with economic costs and environmental impacts. [Methods] By taking the time-dependent reliability meeting the target reliability as a constraint condition, this study established a dual-objective bridge maintenance and reinforcement decision optimization model based on CO₂ emission and economic costs. The non-dominated sorting genetic algorithm II (NSGA-II) was used to analyze the impact of different maintenance and reinforcement schemes on bridge performance, maintenance costs, and CO₂ emission. [Findings] The dual-objective bridge maintenance and reinforcement decision optimization model based on CO₂ emission and economic costs can determine the optimal maintenance and reinforcement scheme for bridges, which ensures bridge safety during the design reference period while minimizing CO₂ emission and maintenance costs relatively. [Conclusions] The proposed dual-objective bridge maintenance and reinforcement decision optimization model provides efficient decision-making solutions for bridge managers and, to a certain extent, contributes to achieving the dual carbon goals.