<p>Permanent magnet eddy current brakes (PMECBs) have great potential for overwinding protection of hoisting containers in ultra-deep shafts. However, the high heat generated during braking is a critical factor limiting their development. Therefore, this study explores the phenomenon of temperature rise in PMECBs used for overwinding protection. First, the working principle of the device is introduced, and its heat generation mechanism is theoretically analyzed using magnetic circuit theory. Then, a finite element model for the PMECB is established to simulate the electromagnetic-thermal coupling behavior during braking. The simulation results reveal a distinct ring-like temperature distribution on the rotor disk surface, with the high-temperature region overlapping the strong-magnetic region by 94.1 %. The radial position of the temperature peak (TP) is located 5 mm inward from the peak magnetic flux density position. Furthermore, as the initial heat generation power increases from 33 kW to 42 kW, the increment in TP diminishes from 3.4 K to 2.5 K, and the time required to reach the TP is reduced. Finally, an experimental braking platform is constructed to validate the simulation results. The findings provide important theoretical support for optimizing the temperature field and safety design of PMECBs in overwinding protection systems.</p>