Recently, with the practice of emission control measure on air pollutant and the transformation of economic structure, atmospheric acid (mainly S and N) deposition shows a downward trend in most areas of China, but keeps increasing in the northwest region. The effects of increasing atmospheric acid deposition on terrestrial ecosystems have been widely confirmed. However, there are few studies on the elemental ecological stoichiometry and its influencing mechanisms in the plant-soil systems around industrial emission sources under accumulating acid deposition. Coal-fired power plant is one of the main industrial sources of acid emission. In this paper, C:N:P ecological stoichiometry in soils, leaves of common plants, and microbes were thus measured around three coal-fired power plants in Ningdong Energy and Chemical Industry Base. The relationships were analyzed between leaf C:N:P ecological stoichiometry and environmental factors (monthly mean deposition of S and N in precipitation and dustfall and soil properties) and also between microbial biomass C:N:P ecological stoichiometry and environmental factors. The results showed that, the variation coefficients were generally higher in soil and microbial biomass C:N:P ecological stoichiometry than those in leaves. The levels of soil organic C, total N, and total P in the study area were higher than those in the same type areas, and the supply of P was more abundant than that of N. Plants might be mainly limited by N, whereas microbes might be P-limited; significantly linear relationships were detected among the three elements in both soils and microbes (P<0.001), whereas insignificant relationships were observe between C and N and also between C and P in leaves (P>0.05). The homeostasis of total N, total P, and N:P were high in leaves. The homeostasis of biomass N:P was higher while those of N and P were lower in microbes, resulting in high sensitivities of microbes to environmental changes in soils; SO₄^2- deposition simulated leaf P uptake and microbial C, N, and P immobilization. Low amount of NO₃^- deposition was beneficial for leaf N absorption, whereas continually increased NO₃^- deposition might intensify P limitation and thus inhibited leaf P uptake and microbial biomass accumulation. Soil enzymatic activity, Ca²⁺, and water content also significantly regulated the C:N:P ecological stoichiometry in leaves and microbes (P<0.05). Therefore, it is necessary to deeply reveal the influencing mechanisms in plant-soil systems around industrial emission sources under accumulating acid deposition with the comprehensive consideration of the soil properties and plant conditions in more power plants on a longer time scale.