Background and aims <p>The global expansion of photovoltaic (PV) panels in drylands causes growing concerns about its ecological consequences. However, it remains unclear how PV panels reshape plant and soil microbial communities. This study investigated the long-term effects of fixed-axis PV panels on plant and soil microbial communities as well as their interactions in a temperate grassland.</p> Methods <p>Based on a field investigation of a temperate grassland with PV panels installed for nine years, we evaluated the changes of the plant and soil microbial communities in the under-panel areas and lower-edge areas compared with the in-between areas. We further explored the relationships between the plant and soil microbial communities.</p> Results <p>Our results indicate a decrease in plant diversity in the under-panel areas and lower-edge areas compared with the in-between areas. The dominance of shade-tolerant (<i>Leymus secalinus</i>) and heliophytic species (<i>Stipa grandis</i>) increased in the under-panel areas and lower-edge areas, respectively. The nitrogen-cycling associated soil prokaryotes showed an enrichment in the under-panel areas, whereas the abundance of carbon-cycling associated soil prokaryotes and arbuscular mycorrhizal fungi decreased significantly. In contrast, the lower-edge areas showed an enrichment of soil copiotrophic prokaryotes and a reduction of arbuscular mycorrhizal fungi. Furthermore, we identified a strong link between the dominant plant species and the composition of soil microbial communities.</p> Conclusion <p>Our findings demonstrate a long-term PV-panel induced reduction of plant diversity in temperate grasslands and highlight a critical role of the shifting dominant plant species in reshaping the soil microbial communities.</p>