To supplement the empirical research on the impact of "double carbon" policy on social economy from the perspective of online public opinion, the "double carbon" policy public opinion index is constructed with the help of search engine Baidu and the VAR-BEKK(DCC)-GARCH(1,1)model is used to scientifically quantify the spillover effect of "double carbon" policy public opinion and metal, chemical and agricultural futures index. The results show that there are one-way mean spillovers and volatility spillovers on the metal index and agricultural index of the "double carbon" policy public opinion index, and the impact of the "double carbon" policy public opinion has a shortterm amplification effect, but the long-term effect is not significant. There are one-way mean spillovers and two-way volatility spillovers between the energy index and the public opinion index of the "two-carbon" policy, indicating that the energy index is most closely related to the public opinion of the "double carbon" policy, and it has strong pricing power. At the same time, it has the function of transmitting public opinion signals to traders. Based on the above findings, from the two levels of government and enterprise, suggestions are put forward, such as "stability first" macro policy, avoiding "sports" carbon reduction, and doing a good job of public opinion monitoring related to "double carbon" policy, and using it to monitor and predict the changes of related indexes.