[Objective] The compound soil of Feldpathic Sandstone and sand in Mu Us Sandy Land belongs to artificial reconstructed soil. The quality evolution of the compound soil after long-term crop planting was studied, in order to provide scientific basis for understanding the structure development and sustainable utilization of the compound soil. [Methods] Based on the field plot experiments of compound soil a with volume ratios of 1:1, 1:2 and 1:5 of Feldpathic Sandstone to sand during the period from 2010 to 2018, the dynamic change characteristics of water-stable aggregates, organic matter content and crop yield in the compound soils under different planting years were analyzed. [Results] With the development of the experiment, the content of water-stable aggregates with diameter>0.25 mm, average weight diameter (MWD) value and organic matter content in the three proportions of compound soils showed an overall increasing trend. After 9 years of planting, water-stable aggregates >0.25 mm in 1:1, 1:2 and 1:5 compound soil increased by 2.71, 3.31 and 4.24 times, respectively, and became the main component of aggregates. The soil organic matter content increased by 8.24, 10.62 and 13.76 times, respectively. In 2011, the potato yield order in different proportion of compound soil was showed as: 1:2 > 1:1 > 1:5, after 8 years of planting, the potato yield increased by 3.27, 4.25 and 6.96 times, respectively, and the yield order was 1:5 > 1:2 > 1:1. Among them, the potato yield in the 1:5 compound soil increased most significantly. The average yield for many years was as high as 53 850 kg/ha, which was equal to the yield of local high-yield fields. [Conclusion] With the increase of potato planting years, the physical and chemical properties of the three-proportion compound soil have been improved, and the compound soil structure has been increasingly optimized. In particular, it can effectively promote the formation of 1:5 compound soil organic and water stable aggregates, and the effect of potato yield increase is the best, so the ratio of 1:5 compound soil is suitable for potato growth.