Abstract: Root-soil system may be considered as a subsystem of the soil-plant-atmosphere continuum (SPAC). Synchronously, dynamic mechanisms in root-soil systems improve water and nutrient supply in the brother SPAC system. Plant root hydraulic lift is a process of root-soil systems that optimizes the homogeneous distribution and use of soil water. This phenomenon is a normal in plant root systems. Plant hydraulic lift processes make it easy to the most use of soil water and to facilitate soil nutrient utilization. Systemic optimization explains the mechanism of root hydraulic lift, which occurrence is restricted by environmental conditions and other inevitable factors. Root hydraulic lift water volume is a non-negligible element of plant growth, which provides a larger portion of water needed for transpiration. Hydraulic lift is not only a transpiration factor, but also a physiological and ecological element of plants. Applied root hydraulic lift research has the potential to improve agricultural development and ecological restoration in draught regions.