Content moderation is a critical issue for media providers to protect viewers from harmful content and also to build a good reputation with the public. Due to the lack of a trustworthy and effective quality management mechanism for content moderation, the heavy workload of content moderation remains difficult for media providers. In this paper, we propose a decentralized management mechanism for content moderation, in which the permissioned blockchain provides credible, transparent and verifiable infrastructure and the smart contracts ensure the automatic execution of pre-set management rules. The proposed mechanism combines a quality evaluation and monetary incentive method based on authenticity historical data, aiming to achieve long-term sustainable quality improvement. Experimental results show that our mechanism can successfully execute the preset management rules automatically, which can simplify the management complexity and avoid human intervention.