Pingding Yutai Coal Mining Face 15104 is an island fully mechanized caving face. In order to improve the recovery rate of the face, through theoretical analysis and numerical simulation, the reasonable width of the coal pillar for the roadway was determined to be 7.0 m, with optimized parameters. It was learned from the monitoring of surrounding rock displacement during field application that the surrounding rock displacement of the roadway was small during the roadway excavation. The surrounding rock displacement was within the safe range during the mining face. The designed coal pillar width and support protection scheme achieved good application results.