Based on the analysis of concepts related to capital and public opinion, this paper explores the relevance between capital and public opinion, and makes a detailed analysis about the new characteristics of the communication of public opinion influenced and controlled by capital and the new features of public opinion struggle. It analyzes the positive influence of capital intervention on public opinion work and the new challenges brought to the public opinion feld in detail, and explores the risks of public opinion safety under the capital in?uence and control from external factors, internal factors and mainstream discourse construction. Based on the above analysis, this paper puts forward concrete ways of preventing capital in?uencing and controlling public opinion from the aspects of culture, policy and industry.