Abstract: To explore the short-term effects of phosphogypsum-based amendment on plant growth and soil environment, a 130-day pot experiment was conducted to systematically analyze the effects of modified phosphogypsum on plant growth indicators, soil physical and chemical properties, and heavy metals and fluorine migration characteristics of soil-crop systems under different dosing ratios. The results showed that during the experimental period, modified phosphogypsum as a soil amendment effectively adjusted soil pH to a stable range, improved soil nutrient availability, and significantly promoted plant growth. Increasing the dosage ratio of modified phosphogypsum could effectively inhibit the migration of heavy metals from soil to plant. Meanwhile, contaminants in both soil and leachate remained below the limits specified in Soil Environmental Quality-Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618-2018) and Standard for Groundwater Quality (GB 14848-2017) in all treatment groups. With the increase of the dosage ratio of modified phosphogypsum, the enrichment coefficient of heavy metals in plant leaves decreased, which to some extent inhibited the transfer of heavy metals from soil to plants. However, some heavy metals still exceeded the limits and the fluorine contents increased with the application of modified phosphogypsum (up to 2.7 times that in the control group). Based on the results of this study, the moderate application ratio (30%-60%) of modified phosphogypsum is the optimal range for promoting plant growth, improving soil physical and chemical properties, and mitigating the risk of heavy metal migration and excessive accumulation of fluorine under short-term experiment conditions.