Consensus mechanisms are fundamental to maintaining consistency in distributed systems. With the advent of Web 3.0, blockchain has revealed limitations of traditional Delegated Proof of Stake (DPoS) consensus mechanisms. To address these issues, we propose a novel Quadratic Voting-based DPoS (Q-DPoS) consensus mechanism. Our approach integrates Quadratic Voting into DPoS to optimize voting

power distribution, vote counting, and reward settlement processes, thereby incentivizing participation from users with lower stakes while reducing the concentration of influence. To prevent the system from reverting to a linear reward structure under Sybil Attacks, we introduce admission rules and vote similarity detection mechanisms to strengthen its robustness. Simulation results demonstrate that Q-DPoS significantly increases voter participation and alleviates stake centralization, thereby enhancing overall decentralization. Additionally, theoretical analysis grounded in game theory confirms that the proposed mechanism effectively diversifies voting preferences, contributing to a more balanced and resilient consensus mechanism suitable for Web 3.0 ecosystem.