This study was carried out to develop a novel slow-release fertilizer, which is based on natural attapulgite (APT) clay as a matrix, guar gum (GG) as an inner coating, and guar gum-g-poly(itaconic acid-co-acrylamide)/humic acid (GG-g-P(IA-co-AM)/HA) superabsorbent polymer as an outer coating. The coated compound fertilizer granules with diameter in the range of 2-3 mm possess low moisture content and high mechanical hardness. The effects of APT matrix, GG, and superabsorbent polymer coatings on nutrients release were explored. The influence of the product on water-holding capacity of soil was determined. The degradation behavior of the GG-g-P(IA-co-AM)/HA outer coating was assessed by examining the weight loss with incubation time in soil. The experimental data and analysis in this study indicated that the product prepared by a simple route can effectively reduce nutrient loss in runoff or leaching, improve soil moisture content, and regulate soil acidity and alkalinity level.