The spread process and evolution mechanism of Internet opinion were studied based on social physics.Three concepts and definitions were put forward,namely,the circulation concentration degree of Internet opinion based on Social Combustion Theory,the Internet opinion organization degree based on Social Behavior Entropy Theory and the criticality degree of Internet opinion circulation based on Social Shock Wave Theory.Addionally,in order to capture,extract and analyze the social effect of Internet opinion circulation,MAS(multiagent system),complex network analysis and data mining were applied to combine “ThreeDegree” method.