In light of the continuous development of Internet technology, many problems involving network security based on the blockchain have also been observed gradually. In this paper, the existence forms of network security hazards based on the blockchain are explored to establish a network blockchain security sharing model based on fuzzy logic. In security sharing, network blockchains are often maintained by many parties. This poses new potential threats and challenges to privacy protection in these multiparty network blockchains. This paper proposes a research scheme for a network blockchain security sharing model based on fuzzy logic. The tampering of the protected network blockchain is prevented by blockchain, and the fuzzy logic algorithm is used to ensure its confidentiality. This solution allows the exchange in the protected network blockchain and the security of transaction information based on the fuzzy logic algorithm. According to the results of the experiments, this method can ensure security sharing of the network blockchain with high practicality and achieve the expected design effect.