Problems of large deformation of surrounding rock, such as large damage range and difficult support, are prominent during the period of gob-side entry driving excavation. Such problems seriously affect the safety and production efficiency in coal mines. To control the deformation of the surrounding rocks in the roadway, reduce supporting pressure, and determine a reasonable design for entry protection coal pillar, a numerical simulation study, theoretical analysis, and actual field measurement analysis were adopted under the engineering background of 7329 working face in Nantun Coal Mine in Jining, Shandong, China to analyze the stress distribution features and the deformation laws of the surrounding rock and the gob lateral supporting pressure distribution features under different coal pillar widths in the return airway of 7329 working face. Finally, on the basis of the combination of the three aforementioned methods, the optimal coal pillar width in a high-stress gob-side entry was proposed. Results show that the amplitude increasing extent in the vertical stress of the coal pillar is large under a small coal pillar width and exhibited linear increase. As the coal pillar width increases, the area of the elastic nuclear region also increases and the stress increasing extent tends to be stable without any apparent increasing trend. Gob-side entry wall deformation decreased with the increase in coal pillar width, whereas the deformation of solid coal wall shows an opposing trend; thus, the size range of a narrow coal pillar in the roadway was determined as 5-6 m. The width of roadway-protecting coal pillar is determined as 6 m through numerical simulation and theoretical analyses. The rationality of 6 m pillar is verified through an industrial test, which effectively solved the difficult support of gob-side entry and large deformation problems. The obtained conclusions could provide a certain reference for reasonable location selection of roadways under similar geological conditions.