Abstract: This is an article in the field of mineral processing engineering. Some unavoidable ions commonly present in the slurry solution have an important influence on the flotation separation of lead-zinc sulfide ore. The unavoidable ions in the slurry mainly come from the water used in the processing plant, the dissolution of minerals, the dissociation of activators or depressants, and the primary ions introduced by the release of fluid inclusions and the secondary ions introduced during the grinding process. This article summarizes and analyzes the effects on the flotation separation of lead-zinc sulfide ore which is caused by the primary ions introduced in the slurry and the secondary inevitable ions introduced in the grinding system. It is found that both primary ions and secondary ions have obvious effects on the flotation behavior of lead-zinc sulfide ore. And many scholars have done a lot of research on this phenomenon. In this paper, a great breakthrough has been made through the adjustment and control of reagents and changes in the grinding environment. At the same time, this article provides important research ideas for follow-up researchers. The focus of this article is how to integrate the previous research results with the field process significantly, how to eliminate inevitable ions from the source without affecting the industrial economy, The important direction of future research is still how to reduce the influence of inevitable ions on the flotation index from the field process.