Network attack model is the basic principle of cyberspace attack operation. This paper analyzes the main problems of the classic Cyber Kill Chain model in three aspects: the lack of applicability, the lack of comprehensiveness and the lack of integrity, and constructs a spiral model of network attack which is more suitable for cyberspace operations. The model describes the network attack action as six stages: reconnaissance, weaponization, penetration and destruction, lateral movement, withdrawal, assessment and improvement, and is set up as a spiral cycle structure. Through the optimization and reconstruction of the attack chain model, the level of the model is clearer, the task is clearer and the function is more complete. On this basis, the attacking tasks and the attacking methods that should be completed in every stage of the model are combed. The principles of applying the spiral attack model in cyberspace offensive operations are discussed. The concealment principle, the advanced principle, the continuity principle and the multiplex principle of the model are put forward, which further enhance the needle of the model. It reduces the operational risk and makes it more suitable for cyberspace operations.