The distribution of a mineral car disc brake coupling field was studied based on direct coupling method of temperature field and stress field.According to the real dimension of the friction pairs,the model of three-dimensional transient thermal-structure coupling finite element was established and the emergency braking condition of mineral car was numerical simulated based on the principle of heat conduction.The results show that there are coupling characteristics between the temperature and stress field,which are shown zonal distribution,the maximum temperature and stress are concentrated on the extrusion area of friction disc and friction plate,and the emergence of maximum stress lags behind the maximum temperature.There is a large temperature gradient in radial and axial direction of friction pairs,which produces large thermal stress and causes thermal shock and thermal fatigue on the brake friction pair materials,and may even lead to crack of brake disc in serious cases.