Abstract: In order to enhance the control effect of rockburst prevention and control of gob-side working faces under thick and hard key strata, an integrated approach encompassing theoretical analysis, numerical simulation, and engineering application was adopted to investigate the main influencing conditions and quantitative determination methods for the rockburst-prevention width of gob-side working faces under thick and hard key strata. Results indicate that both static and dynamic loads during the mining stage of the gob-side working face are significantly influenced by the adjacent goaf. The static load is primarily governed by the pre-mining spatial structure of the overburden and its load transfer mechanism, whereas the dynamic load is predominantly induced by the fracturing of the thick and hard key stratum and the subsequent instability of the spatial structure of the overlying strata during active mining. By considering the overburden characteristics of gob-side working faces beneath thick and hard key strata, the quantitative relationship among transferred load of the overburden (P_c), the goaf width (L), and the fracture height (h) can be established. Taking into account both the pre-mining overburden spatial structure and the movement state of the strata during mining, gob-side working faces were classified into three typical categories: Type：X1+X2, Type X1+ X2, and Type X1+ X2.The bearing capacity and external load of gob-side working faces were identified as the principal factors controlling the working face width. By constructing a ratio function between the bearing capacity and loading force, a comprehensive rockburst mechanical criterion and a quantitative method for determining the optimal rockburst-prevention width of gob-side working faces were established. Combined with field examples of gob-side working faces under thick and hard key strata in different mines, the range of the rockburst-prevention width of the gob-side working face was calculated, and the rationality of the theoretical research was verified by numerical simulation results and the actual rockburst manifestation during mining. Essential theoretical guidance and engineering references are provided by this study for the proactive prevention and robust control of rockburst hazards in gob-side working faces under thick and hard key strata.