Network security is a major challenge faced by industrial control systems today, and on the basis of good technical protection, network security must rely on the improvement of management. This paper researches on the realization of a dynamic industrial control system network security management cycle based on the PDCA model, and introduces the industrial control system network security management practice implemented in A Company. By constructing a network security management system framework, it establishes a complete management system library for unified management, revises and improves the existing system clauses, formulates the basis for reviewing the implementation of the system in key links, conducts regular network security managementself-examinations, and monitors implementations of the system so as to verify the rationality and applicability of the management system, and finally achieve continuous network security.