Abstract: Addressing the issues of poor roof contact and insufficient support strength in existing gob-side entry retaining technologies involving concrete walls and paste walls, a novel "flexible formwork concrete wall" composite support structure is proposed based on the engineering background of Malan Mine. This structure adopts a functional zoning design: the upper part is a high-water material flexible roof contact layer, and the lower part is a high-strength ordinary concrete support layer, forming a composite wall with gradient mechanical properties. Combining coal seam occurrence conditions, geological structures, and theoretical analysis, the overall width, layer height, and other dimensional parameters of the composite wall, as well as the strength matching relationship, are systematically optimized. Field industrial tests have been conducted. The results show that when the overall width of the wall is 1.5 m, with a compressive strength of 15 MPa for the roof contact layer and 40 MPa for the support layer, the composite wall can effectively adapt to the dynamic process of basic roof fracture, ensure long-term stability of the roadside support system, and meet the sealing requirements of the mined-out area.