Abstract: The Intelligent Manufacturing scenario aims at improving the benefit and competitiveness of industries by leveraging the next.generation information technologies, yet making the isolated industrial assets interconnected as Industrial Internet.Since these interconnections extend the attack surfaces, the industrial networks are facing the severe threats from both inside and outside Internet.This paper aims at analyzing the security risk of Industrial Internet under the scenario of Intelligent Manufacturing, and proposing the corresponding technical countermeasures.Specifically, the risk analysis is conducted from three perspectives: risk of supply chain, risk of terminal asset, and risk of stealthy attack.Through investigating the advancement of industrial security techniques, three technologies and their affiliated framework are proposed as countermeasures.The future working directions for protecting Chinese industrial networks are concluded at the end.

Key words: industrial network security, industrial security, risk assessment, active defense