Purpose <p>In this paper, the ecomaterials such as potassium polyacrylate (K-PAM), green vitriol (GV), biochemical humic acid (BHA) and coal-based humic acid (CHA) were selected to improve the soil with poor physical structure, low fertility, low biological activity and difficulties of plant growth in coal mine area.</p> Methods <p>The optimal dosage for soil improvement and plant growth promotion in coal mining areas was determined by orthogonal soil incubation and potting tests.</p> Results <p>The results showed that the physical structure and chemical properties of the soil were significantly optimized (<i>P</i> &lt; 0.05) when the optimum combination of the four materials in the soil was K-PAM:GV:BHA:CHA = 10:1:16:10 compared to the control. After 25 days of soil incubation, the soil bulk density and pH in the optimum group decreased by 18.66 and 2.96%, and the field capacity for water and the available phosphorus increased by 54.56 and 51.40% compared to the control, respectively. The pot experiment showed that when the addition amount of the composite material was 26.25 g/kg, the plant biomass increased significantly (<i>P</i> &lt; 0.05). After 30 days of planting, chlorophyll a and chlorophyll b increased by 24.06% and 63.17% compared with the control group (CK1), root length and plant height increased by 36.52% and 49.89% compared with CK1, and the fresh weight and dry weight of aboveground and underground increased significantly compared with CK1.</p> Conclusion <p>The research results not only provide an economical and environmentally friendly organic and mineral composite material for sustainable soil remediation but also provide an important reference for soil improvement and ecological restoration in mining areas.</p>