The problem of farmland acidification in China is widespread throughout the country, except for the arid northwest region. The situation is particularly prominent in the tropical and subtropical regions of the south and the black soil area of the northeast, causing serious harm to agricultural production and the ecological environment. This article summarizes the main progress made in aluminum activation during soil acidification, the toxicity of soil active aluminum to plants and ecosystems, and the hydrolysis and transformation of active aluminum during amelioration of acidic soils. It analyzes the shortcomings of related researches and proposes several aspects that should be focused on in future research. This paper emphasizes the need to strengthen the research on the mechanisms of aluminum activation during soil acidification and the mechanisms of aluminum hydrolysis and the characteristics of aluminum hydrolysis products during the amelioration of acidic soils, which will provide theoretical basis for the management of acidified farmland and the sustainable utilization of acidic soil resources.