Abstract: In order to study the control mechanism of surface subsidence by the high and huge thick conglomerate strata after working face mining, the typical working face of west 11th mining area of Gaozhuang Coal Mine is taken as the background, and the research is carried out by using the theoretical analysis, numerical simulation, and the actual measurement of surface subsidence; based on the distribution of micro-seismic events, we analyzed the characteristics of overlying strata structure in the working face of the high level huge-thick conglomerate layer, and the high level huge-thick conglomerate layer is less affected by mining, and the degree of fissure development is lower; a mechanical model of Euler-Bernoulli solid-supported cracked beam in giant conglomerate strata was established, and the deflection control equations under the influence of cracks were deduced, which elucidated the control mechanism of giant conglomerate strata on surface subsidence. Numerical simulation results show that the vertical displacement of overlying strata changes abruptly at the bottom of the giant conglomerate strata, the bottom of the giant conglomerate strata is prone to generating off-stratum space, and the off-stratum space undergoes the morphology evolution of “crescent” and “disk”, and the modeled surface subsidence under the influence of the giant conglomerate strata is significantly smaller than that of the giant conglomerate layer. The amount of modeled surface subsidence under the influence of the giant conglomerate layer is significantly smaller. The measured results of surface subsidence show that the amount of surface subsidence of the working face mining in the high level giant thick conglomerate area is obviously smaller, and the high level giant thick conglomerate has an obvious controlling effect on surface subsidence.