In response to the problems of poor soil quality and increasingly severe salinization in Lanzhou New Area, A field experiment was carried out from 2022 to 2023 to explore the effects of two types of crops (C1: Sainfoin, C2: Wheat) and 3 soil improvement methods (A0: traditional fertilization, A1: 9.0 t/hm² woody peat + 3.0 t/hm² organic materials + traditional fertilization, A2: 7.5 t/hm² desulfurized gypsum + 3.0 t/hm² organic materials + traditional fertilization) on soil physiochemical properties, nutrient contents, enzyme activities, microbial carbon and nitrogen of the 0-30 cm cultivated layers, as well as the crop yields of saline-alkali lands in Lanzhou New Area. The results showed that: 1) Compared with A0, the addition of woody peat and desulfurized gypsum effectively reduced soil bulk density, pH and water-soluble salt content, and increased the contents of soil organic carbon, total nitrogen, total phosphorus, total potassium, nitrate nitrogen, ammonium nitrogen, available phosphorus, and available potassium. C1A1 and C2A1 treatments had more obvious effects, but there was no significant difference between them. 2) Compared with A0, the activities of soil invertase, urease, catalase, alkaline phosphatase, and the contents of microbial carbon and nitrogen under C1A1 and C2A1 treatments were significantly increased by 24.74% and 23.61%, 49.48% and 48.14%, 71.32% and 69.77%, 38.37% and 35.93%, 29.54% and 29.68%, 106.26% and 112.51% respectively (P<0.05). 3) The order of soil quality index was: C1A1 (0.68) > C2A1 (0.64) > C1A2 (0.56) > C2A2 (0.54) > C1A0 (0.40) > C2A0 (0.37), the order of the biomass of Sainfoin straw was: C1A1 > C1A2 > C1A0, and the order of the biomass of wheat straw and the grain yield was both: C2A1 > C2A2 > C2A0. There was a significant positive correlations between soil quality index and crop yields (the R² values of the biomass of Sainfoin straw, the biomass of wheat straw and the grain yield were 0.9224, 0.9522 and 0.9415, respectively, P <0.05). In conclusion, for the improvement of saline-alkali soil and the enhancement of soil fertility in Lanzhou New Area, the improvement mode of A1 is recommended.