Soil desertification is one of the most serious environmental problems in the world.Soil fertilization and vegetation restoration are the key links in desertification governance. As a agricultural waste, crop straw still retains rich organic matter and nitrogen, phosphorus and potassium nutrients, and is a natural organic amendment. Granulation of straw can significantly improve straw returning and improve soil fertility.Using agricultural waste (straw) as the main raw material, adding polyacrylamide, microbial agents and NPK fertilizers, and processing them into granulated straw amendment (GSA).In order to investigate the effects of GSA on soil fertilization and vegetation growth in the alpine sandy land of Northwest Sichuan, a field experiment with blank control (CK0), local conventional yak dung treatment (CK1) and four application levels of GSA (6, 12, 18, and 24 t/hm²)were conducted.The results showed that compared with CK0, both GSA and CK1 significantly increased soil total nitrogen, total nitrogen density, total nitrogen storage and nitrate nitrogen content. GSA and CK1 also increased the plant height, total root length, total root surface, average root diameter, root volume and dry weight of single plant (DWSP) of ryegrass(p<0.05). The application of GSA and CK1 increased the soil nitrogen content and promoted the growth of ryegrass.The effect of GSA on the nitrogen content of sandy soil and the growth of ryegrass was better than that of CK1. Compared with CK1, the average of total nitrogen content, total nitrogen density, total nitrogen storage and nitrate nitrogen content increased respectively by 12.50%, 22.73%, 20.90% and 344.56% under the treatment of GSA.The average of shoot and root DWSP of ryegrass also increased respectively by 57.50% and 66.86%, when compared to CK1. Increasing the application rate of GSA can effectively increase soil nitrogen contentand the growth indexes of ryegrass also increases gradually.When the application rate exceeds 18 t/hm², the total nitrogen content, total nitrogen density and total nitrogen storage in the 0-10 cm layer, and the growth indexes of ryegrass are not significantly different.There was a significant correlation between soil nitrogen and DWSP of ryegrass, and the correlation between soil total nitrogen and total nitrogen and DWSP of ryegrass was the highest (r ≥ 0.90^**).The leaching rate of exogenous nutrients decreased at first and then increased with increasing the application rate of GSA, with a minimum at 18 t/hm². Considering the changes of soil nitrogen content, exogenous nutrient leaching rate and growth of ryegrass, the optimum application rate of GSA in sandy soil of northwest Sichuan is 18 t/hm².