Under the global warming， the extreme warming process， heavy snowfall and Rain-On-Snow event occur more frequently， resulting in more frequent snowmelt floods， and the rain， snow and ice mixed floods. Therefore， the projection， prediction， forecasting and early warning of the flood disasters are urgently needed in the arid regions of northwest China. According to the present research progress on key technologies of snowmelt flood disaster forecasting， it is necessary to reveal the mechanism of flood disasters， develop the monitoring and early warning device of snowmelt flood disasters， and then construct the three-dimensional monitoring system in arid areas. Based on the in situ， remote observation and involved research results， a hydrological model should be developed to accurately simulate the rain， snow and ice mixed floods. Therefore， an Intelligent Decision Support System （IDSS） should be constructed to demonstrate the flood submerged areas， evaluate the risk of the flood disasters and give the best solutions in the arid regions of northwest China.