In order to evaluate the improvement effect of different amendments on salinized soil, this study took sunflower as the research object. A field split plot experiment was conducted with 4 treatments:the biochar (DC, 22.5 t/hm²),desulfurization gypsum (DS, 37.5 t/hm²),desulfurization gypsum and organic fertilizer (DSF, 37.5 t/hm²) and the control (DCK). The results showed that the soil bulk density were reduced, and soil porosity was increased by adding amendments, among which the biochar gave the best effect. For the plough layer (0-20 cm), the soil bulk density was decreased by 6.11% after harvest, which was 4 times of the control. Soil porosity was increased by 12.89%, which was 5 times of the control. The desulfurization gypsum had the best effect in reducing soil pH value and electrical conductivity, with the biggest drop of 10.09% and 28.51%, respectively. Different amendments had different effects on soil fertility. Compared with the control, the biochar treatment significantly increased the contents of organic matter, available nitrogen and available phosphorus in surface soil after harvest. The desulfurization gypsum significantly increased the contents of available potassium. The sunflower plant height, stem diameter, dry matter accumulation and 100-grain weight were significantly increased by the different amendments. The highest sunflower yield was observed under the biochar treatment, which was 4 539.60 kg/hm², 32.28% higher than the control. In summary, the soil properties were significantly improved after adding different amendments in the salinized soil of Hetao Irrigation District, leading to the increased sunflower growth and yield. The application of biochar with 22.5 t/hm² had the best effect on the improvement of saline soil, followed by desulfurization gypsum of 37.5 t/hm², both of which could effectively improve soil fertility and sunflower yield.