Soil acidification has become one of the most serious land degradation issues in agricultural systems worldwide. In this paper, we reviewed the natural and anthropogenic driving factors and processes of soil acidification and the influence mechanism of soil acidification on soil inorganic carbon (SIC) and organic carbon (SOC), compared the advantages and disadvantages of organic, inorganic, biological and compound amendments in improving soil acidity, cultivating basic fertility and increasing organic carbon pool. Based on these, to jointly promote soil acidity improvement, basic fertility cultivation and SOC improvement, we have summarized and proposed to (i) establish a quantitative model of the relationship between soil acidity, alkalinity and acid ion composition, construct the interaction mechanism model of soil acidity, basic fertility and organic carbon pool, form a theoretical framework for improving acid soil by ion balance and multifunctional collaboration. (ii) Clarify the synergistic path of soil acid-base ion balance, nutrient ion activation and stabilization of carbon-containing components, as well as the synergistic enhancement technology of soil function for acid reduction, fertilizer cultivation, carbon sequestration and pollution reduction based on the acid-base ion balance classification index of soil and the acid-base ion balance measurement method of the soil-crop system, establish the technology system for precise improving soil acidity by ion balance of fertilizer combined with inorganic amendment, and green improving soil acidity by organic, inorganic and biological multi-functional synergistic. The study can provide a reference for the green and sustainable development of China's agriculture.