It is necessary to consider the mechanism of the runoff yield and flow concentration in the karst area(covered karst area, exposed karst area) and the water movement and transforming relation between karst and non-karst area in the hydrological characteristic analysis in the karst irrigated area. The hydrological circle in karst irrigated area is complex and vulnerable due to the porous and double the floor space underground rock structures and the effect of human activity and water management measure, and it remarkably responses to environment change. Establishment of the distributed hydrological model for karst irrigated area based on the characteristic of the hydrological circle, and application of coupling model of distributed hydrological model and climate change model and human activity parametric model can predict the impacts of environment change on hydrological circle in karst irrigated area. The simulated can be used to make out the coping strategy of agricultural water saving and water resource allocation and provide reference basis for the high efficient utilization of water resources.