In order to solve the problems of short service life and higher thermal deformation of heavy duty vehicle oil cooling disc brake,an oil cooling disc brake is regarded as research subjects,the thermo- mechanical coupling analysis model of oil cooling disc brake is established in brake condition,finally,the influences of the brake disc thickness and cooling oil flow rate on brake friction disc contact surface,the internal stress field,temperature field distribution are got. The results show that the oil cooling disc brake highest temperature and maximum braking stress can meet the use requirements of materials in continuous braking condition. With the increase of the thickness of the brake disc,the brake temperature and stress values show a downward trend.With the increase of oil flow rate,the highest temperature and maximum stress of brake also show a downward trend,and oil cooling disc brake stress value become stable in the oil flow rate of 4 m3/ h.