In this study, the fluvo-aquic soil in the Fengqiu Agro-ecological Experimental Station was taken as the research object, four different fertilization treatments were selected, including no fertilization (CK), regular chemical fertilization (NPK), mushroom residue combined with chemical fertilizer (MRF) and chicken manure combined with chemical fertilizer (CMF), soil physical, chemical and biological indexes were measured as the total data set (TDS), two minimum data sets (MDS1 and MDS2) were derived through principal component analysis and correlation analysis, soil quality index (SQI) was calculated by linear (L) and nonlinear (NL) scoring models respectively, the optimal SQI was found by fitting SQI with crop yield, and the technical measures for soil conservation and fertility improvement were proposed. The results showed that compared with CK, the combined application of organic materials and chemical fertilizer, especially MRF, improved soil physical, chemical, biological properties and crop yield. Soil quality index based on the total data set (SQIT) was significantly positively correlated with the linear and nonlinear soil quality indexes of the two minimum data sets. The nonlinear soil quality index based on MDS2 (SQI2-NL) more accurately evaluated soil quality. Under this evaluation method, SQIs of different fertilization treatments showed MRF (SQI=0.60)>CMF (SQI=0.52)>NPK (SQI=0.48)>CK (SQI=0.36). In conclusion, MRF is beneficial to maintain and improve fluvo-aquic soil quality in the study area.