UNISWAP is a decentralized exchange (DEX), which first introduces an automated market business (AMM) model. Unlike the order book, due to the constant product formula, traders can obtain continuous liquidity. The V2 version was originally based on Ethereum, and then extended to other blockchain supporting ERC-20 tokens. Although the V1 version of Uniswap only supports the exchange of ETH-ERC-20 token pairs, the V2 version solves the bridge problem and introduces lightning exchange. These allow users to exchange different ERC-20 tokes without generating too much slippery point. It also introduces the cost of agreement, which helps the platform's sustainable development. In addition, the V2 version began to use the packaging Ether instead of the local Ether as its core contract. The popularity of the exchange has prompted the V3 version with concentrated liquidity and more flexible costs, which improves the user experience of traders and liquidity providers.