Forest is the main body of the terrestrial ecosystem, and plays a central role in regulating terrestrial ecological balance. At present, the total amount of forest resources are insufficient, and there are increasing demands for wood, which require the development of plantations globally. Soil is the basic resource supporting the growth of plantations and the main site for nutrient transformation and biodiversity protection. To date, the decline of soil fertility has become a serious problem in plantation management in China, severely restricting the sustainable management of forestry production and leading to an increased vulnerability of ecological security barriers. Therefore, it is important to increase our understanding of the formation and impact factors of biological barriers derived from soil fertility decline in plantations and to explore key technology for modulating plantation health and primary productivity. The present study systemically discussed the mechanism of maintaining soil fertility in plantations from soil physical and chemical properties, soil biological community characteristics and functions, and probed the underground ecological processes affecting soil fertility of plantations, including forest age structure, stand density, tree species type and tending management mode. In the future, more attention should be paid to the mechanism of coupling soil's physical, chemical, and biological properties in plantations when the environment changes. Besides, it is necessary to further quantify the interaction model among tree health, soil biology and environment, and to form a comprehensive directional system of regulating plantation health through afforestation, process management, symptom diagnosis and soil fertility modulation, so as to ensure the sustainable and multi-objective management of plantations.