In order to quantitatively identify the controlling factors of overlying strata stability under multi-index conditions and to reveal their response relationships with the failure height of overburden, attention has been focused on the problem of overburden instability and abnormal development of water-conducting fracture zones induced by the superposition of in-situ stress and mining disturbance in coal mining. A case study has been conducted on the 1313(3) working face of the Guqiao Coal Mine. Uniaxial compressive strength (UCS), wave velocity (P), and fractal dimension (FD) have been selected as evaluation indices.A grey relational analysis method has been introduced, and an index sequence matrix has been constructed to determine the influence weights and sensitivity ranking of each indicator. Meanwhile, based on a three-dimensional numerical simulation platform, variations in evaluation indices have been equivalently represented by adjusting shear modulus, cohesion, and pore-scale parameters. Sensitivity analyses have been carried out under ±20% variations from baseline values. During the mining process, the evolution characteristics of the plastic zone and water-conducting fracture zone have been dynamically monitored. In addition, analogy calculations and theoretical verification have been performed using measured data from an adjacent working face.The sensitivity ranking of the controlling factors of overburden stability has been determined as follows: uniaxial compressive strength (0.802) > fractal dimension (0.764) > wave velocity (0.761). As mining advances and overburden failure tends to stabilize, the plastic zone has been observed to exhibit a saddle-shaped spatial distribution characterized by a higher central region and lower sides. Increases in wave velocity and compressive strength have been found to significantly inhibit the development of the water-conducting fracture zone. The theoretically predicted height of the water-conducting fracture zone for the 1313(3) working face has been calculated as 50.4 m, with an error of less than 2 m compared with numerical simulation results.Macroscopic mechanical properties such as rock strength and stiffness have been found to form a mechanical barrier that restrains overburden instability and failure. In contrast, the complexity of microfracture structures, as characterized by fractal dimension, has been shown to govern the final development scale of the water-conducting fracture zone. A multi-index evaluation system based on macroscopic mechanical parameters and microscopic structural characterization parameters has been demonstrated to accurately back-analyze the failure mechanism of overlying strata, thereby providing a fundamental quantitative basis for overburden control and water hazard prevention in mines under similar geological conditions.