Abstract: To address the unclear mechanisms of overburden movement, evolution, and failure under conditions of ultra-thick loose layers and uneven-thickness bedrock, the 3301 panel of a specific mine was selected as the engineering case study. Using physical simulation, numerical simulation, and theoretical analysis, this study investigates the overburden movement process, collapse and filling characteristics, and linkage failure mechanisms under these conditions. An overburden migration model and a trace estimation equation are proposed, accounting for the interactive evolution effects of ultra-thick loose layers and uneven-thickness bedrock. The findings are as follows: ① As bedrock thickness increases from thin to medium-thick to normal thickness, the failure boundary evolves from "symmetric trapezoid" to "asymmetric quasi-trapezoid" to "semi-saddle" shapes. Under the control of uneven-thickness bedrock, the movement of loose layers dynamically changes from a "symmetric funnel" to an "inclined funnel" to a "tilted-bottom funnel." ② Thin bedrock primarily undergoes plastic failure, resulting in irregular filling of goafs after collapse and minimal fragmentation-expansion effects. The prolonged active movement period of the loose layers causes significant surface subsidence. Medium-thick bedrock experiences characteristics between plastic failure and block-type fracturing, forming temporarily unstable structures that provide partial support and restriction on loose layer movement. In contrast, normal-thickness bedrock undergoes "beam-type" fracturing, with the overburden forming stable "hinged and cantilevered" structures. The ultra-thick loose layer applies greater compressive stress to the fractured or collapsed bedrock below, resulting in more pronounced development of collapse and fracture zones compared to conventional strata conditions. ③ Using the 3301 panel as an example, the overburden failure traces at different mining stages were estimated, and the calculated surface subsidence area was 1551.46 m², with a deviation of 7.6% from the measured value. ④ Control strategies are proposed, including height-limited or backfill mining, roadway grouting reinforcement, increasing the yielding capacity of roadway supports, and enhancing the compatibility of the support system.