Abstract: The molybdenum tailings in Hebei Province had been improved through simple mechanical mixing with low−cost additives, facilitating their utilization for soilization. Through single−factor and composite−amended tests, the water retention rate, pH value, and cation exchange capacity (CEC) of molybdenum tailings were significantly enhanced. Results indicated the application of a composite amendment agent, consisting of farmyard manure, montmorillonite, polyacrylamide (PAM), and citric acid, to the molybdenum tailings has significantly enhanced their properties. The saturated water absorption rate of the molybdenum tailings increased to 61.1%, and both the evaporation rate and decline rate of the moisture was significantly reduced. The cation exchange capacity (CEC) reached 10.15 cmol/kg, and the pH value was lowered to 8.08, achieving a level suitable for agricultural cultivation. Additionally, a pot experiment was conducted to assess the growth effect of improved molybdenum tailings on plants. Compared to the initial molybdenum tailings, the height and quality of plant growth in composite−amended molybdenum tailings increased by 77.4% and 98.1%, respectively. Furthermore, after 15 days of plant growth, the water retention, pH value, and CEC of the composite−amended molybdenum tailings reached levels comparable to those of normal soil, confirming the successful transformation of molybdenum tailings into plantable soil.