Arbuscular mycorrhizal fungi (AMF) can form symbionts with host plants and are widely found in terrestrial ecosystems. A large number of studies have shown that plants inoculated with AMF have stronger water absorption capacity and higher water use efficiency than plants not inoculated with AMF under different water conditions. Under drought and salt stress, AMF inoculation can effectively improve the drought and salt tolerances of host plants. This paper summarizes the research progresses of AMF, which is symbiotic with plants and can enhance the water absorption capacity of plant roots by enlarging root absorption area and improving root structure under different water conditions. The formation of extra-root hyphae networks in soil not only adds a new water absorption pathway (mycorrhizal pathway) to plants, but also regulates the water absorption by improving the mineral nutrition in plants, thus affecting the water absorption status of plants. Under different water conditions, the photosynthesis, transpiration and stomatal conductance of plants are all enhanced after AMF infection of roots. The enhancement of transpiration can directly and effectively improve the transpiration force of plants, thereby improving the absorption capacity of plants to water. At the same time, AMF inoculation can improve the water use efficiency, transpiration rate and net photosynthetic rate of plants, and improve the water use capacity of plants. Further, this paper reviews the serious influence of water stress (including drought and salt stresses) on plant water status, and inoculating AMF can improve the stress tolerance of plants by effectively adjusting the content of osmotic regulation substances in plants under water stress, the activity of antioxidant enzymes, the balance of ions in plants, and by enhancing the levels of plant photosynthesis and transpiration. This paper also discusses the research frontiers on the effects of AMF on water status and salt resistance of plants under different water conditions in order to provide theoretical reference for the improvement of plant water status through mycorrhizal interaction.