In the regions short of water, the adjustment of cropping structure is also an important measure to save water in agriculture besides water-saving irrigation techniques and cultivation techniques. Considering the harmonious development of economy, society and ecology, the thesis established a multi-objective fuzzy optimization model for regional water-saving cropping structure which conquers the limitation that economic benefit is regarded but social and ecological benefits are ignored in the previous studies. The multi-objective fuzzy optimization model is applied in the study for water-saving cropping structure adjustment in North China where the water scarcity is very serious. The result of calculation presents an optimized schedule of water-saving cropping structure in 2010 and 2030. The planting proportion of crops with high water consumption is reduced and that of low water consumption was increased in the schedule, and water use efficiency is improved gradually.