Abstract: Abstract: Hetao region is an important production base of commodity grain and oil crops in China. The large-scale water transferred from outside the river in a long term has resulted in the most headraces and drainage system, covering many cultivated lands in this region. However, human activities have posed a great change on the original hydrological cycle and the natural environment. Some spatio-temporal features, and the process of water conversion and movement are extremely complicated, due to the variation of hydrological cycle elements. In this study, a Water Allocation and Cycle Model (WACM4.0) was constructed suitable for the regions with strong human activities based on the "natural-artificial" composite water cycle theory. The WACM4.0 model was applied to simulate the evolution law and characteristic of hydrological cycle of each mountain-water-forest-cropland-lake-grass system in Hetao region. The main findings are as follows: In the hydrological cycle process, 1) the Wuliangsuhai was mainly characterized by lateral movement of water diversion and drainage, 2) the Wuhai mudflat was the vertical movement of groundwater recharge-evaporation, 3) Haizi region was dominated by vertical and horizontal comprehensive movement characteristics, 4) the cultivated land was the vertical movement characteristics of irrigation water infiltration-evapotranspiration, 5) the planted forest, grassland, unutilized land, and construction sites were the vertical movement characteristics of rainfall-infiltration-phreatic water evaporation, 6) the drainage and channels were drainage water-lateral movement characteristics of drainage water, and 7) the overall system of mountain-water-forest-cropland-lake-grass was the vertical water cycle of irrigation (precipitation)-infiltration-evaporation. The amount of groundwater in Hetao region has been losing year by year, indicating the characteristic of "negative water balance" vertical movement in the circulation process. Specifically, the water from the Yellow River entered the cropland through water diversion channels, leading to the formation of soil water from irrigation water, and then infiltrated the groundwater aquifer, while the remaining water went into the drainage channels, indicating the amount of leakage in this process can be used to replenish groundwater. Two part of groundwater can be divided, one was used to replenish Haizi and Wuhai mudflat, and another part of water consumed away via phreatic water evaporation of artificial cultivated land, grassland, unutilized land, and construction site. The water in drainage channels entered Wuliangsuhai, with the loss water through surface evaporation, while the remained water discharged into the Yellow River through the Wumaoji escape gate. The average annual runoff of the Yellow River can be consumed away by approximately 4.2 billion m3 due to diversion irrigation in the Hetao region. The amount of the Yellow River water consumed by each system was as follows: the water consumption of cultivated land was 3.02 billion m3, the grassland was 114 million m3, the unutilized land was 65 million m3, Haizi region was 116 million m3, the Wuliangsuhai was 289 million m3, the Wuhai mudflat was 83 million m3, the planted forest was 91 million m3, the construction site was 0.09 million m3, the headrace channel was 309 million m3, and the drainage channel was 125 million m3. The research findings can provide a basic support for irrigation management, utilization of water resources, and ecological protection of mountain-water-forest-cropland-lake-grass system.