All terrestrial life originates from the soil, and where there is soil, there is food. Arable land constitutes the foundation of food production. In China, the degradation of cultivated land has long been a prominent issue, arising from the combined impacts of anthropogenic activities and natural factors. Soil acidification is inherently a slow pedogenic process; however, its progression has been markedly accelerated by human-induced factors, such as the long-term excessive application of nitrogen fertilizers and the continuous removal of nutrients through crop harvesting. Acidification reduces the soil’s nutrient-supplying capacity while enhancing the solubility of toxic elements, notably aluminum, which damages rice roots, thereby restricting their normal growth and yield formation. This paper aims to provide a comprehensive review of the current status and principal causes of paddy soil acidification, to examine its impacts on soil fertility and rice production, to synthesize the effectiveness of existing technical measures for its mitigation, and to explore future research directions. The ultimate objective is to establish a theoretical and practical basis for the amelioration of paddy soil acidification, safeguard the ecological health of paddy field systems, and ensure the sustainable development of rice production.