Soil mineral nutrients and fruit qualities of 74 Citrus sinensis Osbeck orchards in the main producing areas of Hunan Province were investigated and analyzed in order to explore the effects of soil nutrients on fruit quality, find out the problems in soil nutrients, and provide reference for guiding scientific fertilization to improve fruit quality. The multivariate statistical analysis of R and LINGO software were used to screen the main soil nutrient factors affecting fruit quality, and the optimal soil nutrient optimization plan was found with the best fruit quality. The results showed that more than 86.20% of the orchard soils were acidic to strong acid, 65.52%, 75.86% and 82.76% of the orchard soils were deficient in exchangeable Ca, Mg, and available B. The fruit quality of Citrus sinensis Osbeck was the result of the combined action of multiple soil nutrient factors. Partial least squares regression analysis showed that the factors that have greater impact on the fruit mass of Citrus sinensis Osbeck were soil alkaline N and exchangeable Ca. The fruit shape index was mainly affected by soil available P, Cu, Zn and pH. Total soluble solid content mainly affected by soil organic matter, available Cu, Zn and pH. Titratable acid content mainly affected by soil available K, B and pH. Vc content mainly affected by soil organic matter, available P, K, Mg and pH. The linear programming solution found that the quality of Citrus sinensis Osbeck was the best with pH of 5.50-6.50, soil organic matter content greater than 39.68 g/kg, alkaline nitrogen within 169.17-170.41 mg/kg, effective phosphorus of 34.50 mg/kg, available potassium within 158.95-160.88 mg/kg, exchangeable calcium of 1 954.69 mg/kg, exchangeable magnesium of 123.81 mg/kg, effective iron of 468.31 mg/kg, effective manganese of 96.09 mg/kg, effective copper of 1.73 mg/kg, effective zinc of 10.93 mg/kg, effective boron of 0.33-0.85 mg/kg. Adjusting soil pH, adding organic fertilizer, timely supplying Ca, Mg and B fertilizers are key to fruit quality management in the future.