To solve the security problem of Hyperledger Fabric caused by the use of fixed endorsement nodes for endorsement, this study proposes an optimization scheme based on a verifiable delay function for the endorsement policy of Hyperledger Fabric. Considering that the verifiable delay function cannot be calculated in parallel but can be efficiently verified, a Fabric transaction model that anonymously and randomly selects endorsement nodes is designed to enhance the security of Fabric transaction endorsement. The experimental comparison between the optimized scheme and the original one verifies that the optimized scheme not only enhances security but also improves efficiency.