<p>Lingonberry (<i>Vaccinium</i> <i>vitis-idaea</i> L.) is an understory shrub esteemed for its unique ecological functions and economic value within the forests of northern China. Soil microbial consortia can improve soil quality and increase plant growth through synergistic interactions among microbial species. However, the tripartite interactions among soil microbial communities, lingonberry, and soil remain poorly understood. This study analyzed the structure and characteristics of rhizospheric fungal communities in lingonberry, isolated and verified mycorrhizal fungi that can promote lingonberry growth, and evaluated the effects of their combined application. The results revealed that soil pH, organic carbon (SOC), water content, and altitude significantly influenced fungal diversity. A beneficial fungal consortium consisting of the strains <i>Arachnopeziza aurata</i> and <i>Oidiodendron maius</i> significantly increased plant height, plant weight, SOC, soil NH₄⁺-N, and soil NO₃⁻-N and the expression of growth-related genes (<i>VvmatK</i> and <i>VvPsbA</i>) in lingonberries. In vitro interaction assays demonstrated that the interaction between <i>A. aurata</i> and <i>O. maius</i> improved mycelial growth quality and increased extracellular enzyme activity. Overall, this study demonstrated that a beneficial fungal consortium can activate positive plant–microbe feedback that concomitantly enhances soil fertility and lingonberry productivity, thereby providing a microbe-assisted strategy for understory vegetation management and soil health restoration.</p>