Since the emergence of Bitcoin (BTC) as a cryptocurrency, blockchain, its underlying technology, has garnered significant attention from academia and industry. Unlike the traditional trust-based centralized model, the core principle of blockchain is “decentralization.” Therefore, this decentralized approach presents a major challenge: achieving consensuses on data among all nodes in networks. This challenge led to the development of research on consensus mechanisms. Proof of Work (PoW), the original consensus mechanism, was initially employed by Bitcoin. However, due to the drawbacks of high-energy consumption during mining, low throughput, and poor scalability in PoW-based systems, alternative solutions such as Proof of Stake (PoS), Delegated Proof of Stake (DPoS), and Practical Byzantine Fault Tolerance (PBFT) have emerged successively. These alternative solutions aim to address the disadvantages of existing systems. In addition to proposing individual consensus mechanisms, there are two directions of the research: combining existing mechanisms to leverage the advantages of each, or addressing original shortcomings of single mechanisms through correction and enhancement, or even both approaches simultaneously. The research on consensus mechanisms in the future will drive the development of blockchain towards achieving high-throughput, scalability, decentralization, and low energy consumption.