The capstone project is an electronic voting system based on blockchain, realizing the security requirements of fairness and anonymity in democratic elections. In this paper, we solved the question, “How to design a blockchain-based voting system?” Blockchain technology has the characteristics of a decentralized network, non-tamper with data, and open and transparent information. It can replace the traditional trusted third party and provide the uncentralized trusted service. In the voting system, We need to build a smart contract to Define our process. On the platform choice, choose to create a modular, extensible blockchain development framework: ethereum. Simultaneously, the project also wants to use a hash function, asymmetric encryption algorithm, data certificate, and so on to ensure the system’s security in the technical selection. This project is based on the Remix IDE and Solidity, combining ethereum to provide useful electronic voting ideas.