Abstract: In response to security and privacy in the integration of blockchain technology with federated learning (FL), comprehensive review and analysis of the relevant methods for empowering FL with blockchain are provided. First, FL and blockchain were elucidated separately, and on the basis of this, the state-of-the-art general architectures for blockchain-enabled FL were summarized. Second, the progress in security, privacy, incentives, and efficiency methods was investigated, and the advantages and disadvantages of each method were analyzed. Finally, the current issues in blockchain enabled FL were identified, and potential solutions were proposed, along with future prospects.