Fake news not only leads to misconceptions and damages people's right to know the truth， but also reduces the credibility of news websites. In view of the occurrence of fake news in news websites， a fake news detection method based on blockchain technology was proposed. Firstly， the smart contract was invoked to randomly assign reviewers for the news for determining the authenticity of the news. Then， the credibility of the review results was improved by adjusting the number of reviewers and ensuring the number of effective reviewers. At the same time， the incentive mechanism was designed with rewards distributed according to the reviewers' behaviors， and the reviewers' behaviors and rewards were analyzed by game theory. In order to gain the maximum benefit， the reviewers' behaviors should be honest. An auditing mechanism was designed to detect malicious reviewers to improve system security. Finally， a simple blockchain fake news detection system was implemented by using Ethereum smart contract and simulated for fake news detection， and the results show that the accuracy of news authenticity detection of the proposed method reaches 95%， indicating that the proposed method can effectively prevent the release of fake news.