Abstract: Deformation and instability of gob-side entry retaining in semi-coal-rock roadways are prominent under deep mine high stress conditions. Side wall bulging is the most severe failure mode, which easily leads to large roadway deformation and structural failure, and restricts safe and efficient mining. Taking the roof-cutting gob-side entry retaining of working face C1205 in Chiyu Coal Mine as the engineering background, theoretical calculation, numerical simulation and field test are comprehensively adopted. The large deformation and instability mechanism of surrounding rock in the original entry retaining scheme with high-water material roadside filling is analyzed under the combined effects of high stress, low self-bearing capacity of surrounding rock, support failure, unfavorable roadway layout and insufficient roof cutting resistance of roadside support body. Key parameters of blasting roof cutting are determined through theoretical calculation. Numerical simulation is conducted to reveal the influences of roof cutting height and angle on stress distribution and deformation characteristics of surrounding rock. The results show that surrounding rock stress transfers towards the deep solid coal side with the increase of cutting height and angle. Within a reasonable range, roof cutting height is positively correlated with pressure relief effect, while a critical value exists for cutting angle, the optimal pressure relief performance is at a cutting height of 8 m and a cutting angle of 15°. A zonal reinforced support technology combining advance roof cutting pressure relief, internal anchor cable reinforcement and roadside U-shaped steel gangue retaining is proposed. Relevant support parameters are optimized and verified via industrial tests. After roadway stabilization, the roof-to-floor convergence is 393 mm, the rib-to-rib convergence is 336 mm, and the anchor cable stress remains stable within 205-223 kN. Satisfactory surrounding rock control effect is realized, and the retained roadway can be reused safely.