There are two main contradictions in the existing electronic voting schemes, one is to ensure the legality and compliance of election behavior while ensuring the anonymity of election process, and the other is to ensure the privacy security of ballot information while ensuring the public verifiability of election results. Focusing on these contradictions, a decentralized electronic voting scheme based on Ethereum blockchain and zero-knowledge proof was proposed. In the proposed scheme, the non-interactive zero-knowledge proof algorithm and decentralized blockchain architecture were fused to build zero knowledge proof of voter identity and zero knowledge proof of ballot legality. And smart contract and Paillier algorithm were used to realize self-counting without trusted third-party counting mechanism. The theoretical analysis and simulation results show that the scheme can achieve security requirements of electronic voting and can be applied to small-scale community election.