Taking gob-side entry retaining with large mining height (GER-LMH) of the 4211 panel in the Liujiazhuang coal mine as the engineering background, a numerical simulation was conducted to study the surrounding rock deformation, stress, and plastic zone distribution of GER-LMH with respect to retained entry width. The concept of critical retained entry width of GER-LMH was proposed. In view of the deformation characteristics of surrounding rock, an innovative approach to determine the critical width of GER-LMH based on the cusp catastrophe theory was proposed. The cusp catastrophe functions were set up by approximate roadside backfill body rib convergence and roof subsidence series with respect to different retained entry widths. The critical retained entry width of GER-LMH was 4.0 m according to bifurcation set equations. Surrounding rock stability control principle and technique of GER-LMH was proposed, including “rib strengthening and roof control”: road-in support with high pre-stress rockbolts and anchor cables, roadside backfill body construction technology with high-water quick consolidated filling materials and counter-pulled rockbolt, road-in reinforced support technology with hydraulic prop support and roof master. Field test and field monitoring results show that GER-LMH with supercritical retained entry width in the 4211 panel could meet the requirements for ventilation when the 4211 panel was retreating.

Gob-side entry retained technology is of great significance to develop coal mining industry sustainably, which can improve the coal recovery rate by mining without the coal pillar. However, scholars and researchers pay little attention to the gob-side entry retained with soft roof, floor, and seam in thin coal seams. In this study, the difficulties and key points of surrounding rock control for gob-side entry retained with soft roof, floor, and seam in thin coal seams were firstly proposed. Secondly, the mechanical model of the interaction between the roadside backfill body and the roof for gob-side entry retained with soft roof, floor, and seam in thin coal seams was established, and the relevant parameters were designed. Finally, the above results were verified by the engineering practice of gob-side entry retained technology and the monitoring of mine pressure on the 1103 working face of the Heilong Coal Mine. Moreover, the effect factors of surrounding rock stability for gob-side entry retained with soft roof, floor, and seam in thin coal seams were discussed using the discrete element method. The results could provide guidance for gob-side entry retained with soft roof, floor, and seam in thin coal seams under similar geological conditions.