Secondary public opinion of network politics is that rising after the original political public opinion. It may misguide as well as guide the public. It may rise from diverse sources, change in spreading and produce complex results. It results from five factors: combined force of anonymity, invisibility and high efficiency of the network space; contamination resulted from network populism, nonmainstream political consciousness and the “vacuum” of network management; influence on the authenticity of political information by diversified subject, distorted content and panentertainment of political discourse; impact on political security caused by the differential communication of circle of friends, opinion leaders control of public opinion and network violence in suppressing speech; netizen mobbing, extreme emotions and imitating hypnotic group psychology. Rectification of secondary public opinion on the Internet should be approached from the following aspects: construction of control and early warning mechanism, optimization of network platform control system, strengthening the ideological guiding, defining the responsibility in guiding public opinion and governmental guidance of the netizens in creating a harmonious public opinion atmosphere in order to guide the network public opinion in case of emergency.