Taking the 4303 working face of Shaqu Coal Mine as the engineering background, aiming at the lack of bending resistance of roadway gangue retaining structure, a comparative study of I-steel and retractable U-steel gangue retaining support structure was carried out. Through theoretical analysis, numerical simulation and field application, the supporting structure of gangue retaining wall is compared. Firstly, the force mechanism of the gangue retaining structure is clarified by theoretical analysis. The gangue retaining structure is equivalent to the simply supported beam structure. The mechanical model of the gangue retaining structure is established, and the bending resistance of the two gangue retaining structures is compared and analyzed. Secondly, ABAQUS numerical simulation software is used to establish the model of I-steel and retractable U-steel gangue retaining structure. The bending characteristics of I-steel and retractable U-steel gangue retaining structures under the same stress state are compared. The bending characteristics of retractable U-steel gangue retaining structures with different lap lengths are compared. The results show that the retractable U-steel gangue retaining structure has better bending resistance than the I-steel gangue retaining structure. Increasing the lap length can improve the bending resistance of the gangue retaining structure. Finally, on the basis of the above research, a reasonable field design scheme of retractable U-shaped steel gangue retaining structure is proposed, which has achieved good field application results.