To learn the effects of mixed tree species on soil quality in Ulanqab, screen out the beneficial project of tree growth and soil improvement and improve ecological benefits and economic benefits, Armeniaca sibirica (L. ) Lam, Caragana korshinskii Kom. and Hippophae rhamnoides L. pure stands were selected as controls in the combination of three seedlings planting in pairs by inter-row mixing, intra-row mixing and block mixing in this study, to study the difference of tree growth and evaluate the differences in soil physical properties on entropy weight TOPSIS method. The results showed that block mixing of A. caragana and C. korshinskii could improve the survival rate of trees, increase plant height, ground diameter and other growth indexes, reduce soil bulk density, increase soil moisture capacity and porosity. The comprehensive evaluation of entropy weight TOPSIS method showed that the block mixing of A. caragana and C. korshinskii was better than other mixed tree species in improving soil physical properties; the correlation tests showed that soil bulk density was negatively correlated with maximum moisture capacity, minimum moisture capacity, capillary moisture capacity and total porosity. In all, seedling growth, soil physical properties and soil moisture capacity could interact with each other, selecting appropriate seedling configuration and cultivation technology could effectively improve soil quality and promote the growth of seedlings.