The accumulation of emergency braking at high speed and heavy load may result in the initiation and expansion of thermal fatigue cracks on the surface of brake, then cause the potential risk such as brake wheel crack or even burst. Aiming at the emergency braking condition of the SBD80-A disc brake used in a company's port crane, a finite element analysis (FEA) simulation model was established for the thermal–mechanical performance analysis applying ABAQUS software. Firstly, FEA simulation was employed to obtain the variation process of thermal stress, and the stress cycle load of a single emergency brake was analysed by using the rain flow counting method simultaneously. And the stress–strain curve of the brake material was used to convert stress amplitude into the strain amplitude. Then, the strain life of one-time emergency brake was calculated under different strain amplitudes by utilizing the Manson-Coffin strain-life formula corresponding to the actual temperature. Finally, the Miner's rule was adopted to propose thermal fatigue life prediction method under emergency braking of disc brake considering the influence of high temperature. The research provides a theoretical basis for failure mechanism analysis and life prediction of thermal fatigue for the mechanical products with similar structures, offers a design guidance for determining the inspection and maintenance cycle of brakes under the condition of emergency braking.