The invention relates to a compound fertilizer for field crops planted in arid regions, semiarid regions and desert regions, and particularly relates to a slow-release water-retaining compound fertilizer composition. The slow-release water-retaining compound fertilizer composition is prepared from the following raw materials in parts by weight: 5-6 parts of urea, 5-6 parts of potassium dihydrogen phosphate, 15-16 parts of diammonium phosphate, 2-3 parts of fulvic acid, 13-18 parts of humic acid, 8-10 parts of attapulgite, 1-1.5 parts of ethylene diamine tetraacetic acid, 1-1.5 parts of citric acid, 15-16 parts of ferrous sulfate, 12.5-14 parts of calcium carbonate, 7-8 parts of zinc sulfate, 4.5-6 parts of borax, 1-1.5 parts of iodine ore powder and 1-1.5 parts of molybdenum ore powder. The slow-release water-retaining compound fertilizer composition has the functions of salt tolerance, drought resistance, water saving, water retaining, nutrition, slow release, rootage, soil structure improvement and the like, can enhance the effective utilization rate of the fertilizer and reduce the pollution to soil, and is applicable to forest planting, desert control, field crops, greenhouse vegetables, fruit trees, traditional Chinese medicinal materials, flowers and the like in arid and semiarid regions.