Blockchain technology has brought new changes to cryptocurrencies and has been widely used. However, it still faces the needs and goals of high throughput, low transaction latency, security, and decentralization. In addition, the willingness of consumption nodes (i.e., transaction providers) is difficult to be mapped into leaders, and block miners are keen on mining competitions, which also leads to intensified centralization and energy consumption. To this end, a new consensus algorithm, PoM (proof-of-market), and its first implementation case, the Achain protocol, are proposed. The algorithm is different from the traditional PoW (proof-of-work) consensus, and its design enables consumer nodes to perform PoW and vote for leader nodes, which not only discretizes the mining, improves decentralization, and reduces energy consumption but also reflects the willingness of consumer nodes. In other words, only the node mainly supported can become the leader. In terms of performance, Achain also improves scalability compared with PoW-type blockchains, and it provides a solution for node storage and optimization, which is called FastAchain. In terms of security, Achain is supplemented by a set of incentive-compatible reward and punishment mechanisms to make malicious nodes have negative revenue expectations, which protects the interests of honest nodes, and Achain can tolerate up to 1/3 of the total network computing power being controlled by the malicious nodes. In order to verify Achain’s performance, a prototype of Achain under a large-scale network is implemented for evaluation. The results show that Achain has achieved expectations, outperformed some mainstream representative blockchain protocols, and maintained positive chain convergence and decentralization.