Aiming at the problem of poor water and fertilizer retention ability of sandy soil in northwest China，a pot experiment was conducted to study the effects of organic acid soil conditioner on soil water and nutrient status and the emergence rates of common vetch and maize planted in aeolian sandy soil，a kind of barrier soil in northwest china，under four different conditioner dosages(0，20，40，60 g/kg).The variance analysis and principal component analysis were used for comprehensive evaluation to provide theoretical basis for rational use of organic acid soil conditioners to improve the physical and chemical properties of aeolian sandy soil.The results showed that the contents of soil available and total nutrients and the proportion of available nutrients were significantly increased under the application of organic acid conditioner. The contents of soil hydrolyzable nitrogen，available phosphorus and available potassium increased by 167.01%，300.25%，74.32% and 70.00%，212.84%，108.28%，respectively，when common vetch and maize were planted in aeolian sandy soil with 60 g/kg conditioner dosage rate.The total amount of water evaporation loss in crop growth period decreased with the increase of soil conditioner dosage.When the dosage of conditioner was 60 g/kg，the evaporation losses of common vetch and maize were significantly decreased by 22.43% and 32.42% compared with those without conditioner. However，the emergence rates of the two crops increased first and then decreased with the increase of conditioner dosage，and reached the peak when the conditioner dosage was 20 g/kg.The results of soil salt determination also showed that in addition to beneficial elements such as potassium，calcium and magnesium ions，sodium ions and chloride ions also increased significantly with the increase of conditioner dosage，but the difference in total salt content was not significant.The principal component analysis was used to conduct a comprehensive analysis of 15 indicators.The results showed that the comprehensive score increased with the increase of the dosage of organic acid soil conditioner.Therefore，the optimal dosage of conditioner on aeolian sandy soil was 60 g/kg.