Salvia miltiorrhiza, a widely used traditional Chinese medicine, has been extensively studied for its pharmacol. properties and therapeutic applications in various medical conditions.Due to the lack of scientific fertilization guidance in agricultural cultivation, the excessive use of chem. fertilizer resulted in the decrease of the content of tanshinones in the root of S. miltiorrhiza.This study, through field fertilization trials and pot-based inoculation experiments, aims to explore the effects of fertilization type and amount on the quality of S. miltiorrhiza and the microbial communities in different ecol. niches, while elucidating the mechanisms by which key strains regulate the quality of the Chinese medicinal herbs.In the current study, microbial organic compound fertilizers enhanced rhizosphere soil physicochem. properties, the diversity of rhizosphere soil bacterial community and the network complexity of rhizosphere soil fungi community, and the yield and quality of S. miltiorrhiza.The high-level (300 g/m2) microbial organic compound fertilizer application treatment (SXH) showed the most enhancement in the production of tanshinone compounds in S. miltiorrhiza.Through the structural equation modeling (SEM) anal., soil bacterial community had the greatest impact on the production of tanshinone compounds in S. miltiorrhiza, followed by pH, organic matter, and alk. nitrogen.Addnl., this study identified two core microorganisms, Sphingomonas daechungensis and Nitrospira japonica, in the rhizosphere soil of S. miltiorrhiza, which were related to tanshinone synthesis pathway.Inoculation with Sph. daechungensis bacterial suspension significantly enhanced both the biomass of S. miltiorrhiza and the accumulation of its active compoundsIn conclusion, microbial organic compound fertilizer demonstrates superior efficacy in enhancing the quality of S. miltiorrhiza compared to chem. fertilizers.Under high fertilization rates, the core microbial species become more enriched, thereby further improving the quality of S. miltiorrhiza.This research provides a scientific basis for targeted cultivation practices aimed at producing high-quality S. miltiorrhiza.