The relationship between biodiversity and ecosystem functioning has been a hot topic in the research field of ecology. Research in recent years has shown that plant diversity not only influences above-ground ecosystem function, such as primary productivity, it also influences below-ground biodiversity and soil ecosystem processes indirectly. This review summarizes the effects of plant diversity on soil fauna and the main mechanisms. Plant diversity may affect soil fauna through several pathways, such as changing the quantity and diversity of resource input to soil, the microhabitat structure and soil environment factors. There are still a lot of controversies about how soil fauna responds to plant diversity. This review emphasizes several further researches, including the impact factors influencing plant diversity and soil fauna relationships, the subsequent ecological effects and feedbacks, quantification of the contribution of different mechanisms and pathways.