Abstract: The accumulation of microplastics in farmland is rapidly increasing, posing potential harm to the function and health of the soil ecosystem. The environmental risk and biosecurity of microplastics have increasingly drawn attention. The majority of microplastics in arable soil primarily originate from the use of agricultural films and are predominantly found in areas with soil water deficit, where soil water is the core factor limiting crop growth. Here the current research progress of the effects of microplastics on soil physical properties was systematically summarized, focusing on soil structure, soil water content and soil water cycle. The main findings were reviewed. ① Microplastics could impact soil agglomeration and pore structure by altering soil solid phase composition, aggregate formation and stability. (2) Microplastics altered soil pore structure and increased soil water repellency, resulting in reduced soil water holding capacity in most studies. (3) Microplastics promoted the occurrence of preferential flow, but there was no consensus on soil water infiltration and evaporation processes. (4) Microplastics affected the ability of crops to absorb soil water by blocking the surface pores of crop roots or being directly absorbed by roots. Overall, the effects of microplastics on soil hydrological processes in farmland are influenced by various factors, such as the type, size, concentration of microplastics, soil types, and crop types. The combinations of these factors and their effects still require further study in field.