Blockchain has been given high expectations in recent years. The application of blockchain has already extended to ICT and network security fields from finance. And the issues of blockchain security is being brought to the table. As a revolutionary new technology in the Internet era, blockchain is accelerating its combination with existing technology and constantly generating new business model. Meanwhile, it’s also becoming a challenge to network security regulation mode. This paper conducts a comprehensive research on blockchain in cybersecurity, and analyses the security issues we still face. In future works, more efforts will be done to addressing the security problems of blockchain and exploring better solutions, including the standards for blockchain security requirements and technology testing, mechanism for securing the business flow, clarifying security operations in blockchain, etc.F. Dai, Y. Shi, N. Meng, L. Wei and Z. Ye, “From Bitcoin to cybersecurity: A comparative study of blockchain application and security issues,” 2017 4th International Conference on Systems and Informatics (ICSAI), Hangzhou, China, 2017, pp. 975-979, doi: 10.1109/ICSAI.2017.8248427.