Soil quality is the main bottleneck restricting the healthy and sustainable development of mountain orchards in the hilly region of Loess Plateau. In order to solve the problems of poor soil water holding capacity, low fertility and single microbial community structure in the Loess Plateau, three amendments were selected and five treatments were set up in this study:biochar application rate was at 5% of soil weight (BC), bacillus subtilis application rate was at 0.25% of soil weight (PGBS), bacillus glia application rate was at 0.25% of soil weight (PGBM), humic acid water retaining agent application rate was at 0.1% of soil weight (SAP), and not application any amendment as a control (CK). The relevant indexes were selected by principal component analysis (PCA) and minimum data set (MDS) to comprehensively evaluate soil quality. The results showed that soil total nitrogen, available phosphorus, β-1,4-glucosidase, fungal Chao1 index, cellulase and bacterial Chao1 index had a significant effect on soil quality, and application of soil amendments could significantly improve the soil quality in apple orchards. The improvement effects of different amendments on soil quality as follows:BC > SAP> PGBS > PGBM through a comprehensive evaluation. Considering soil quality and cost, water retaining agent is more suitable for soil quality improvement in mountain apple orchards in the hilly region of Loess Plateau. Biochar has great application potential in soil amendment, if agricultural and forestry wastes can be recycled.