Abstract: In this paper, taking the motor and trailer wheel pairs of 350 km/h EMU as the research object, the ANSYS software is used to simulate the transfer process of the heat generated by the wheel-mounted brake disc during the emergency braking between wheel disc, wheel and axle during braking and after stopping, and the transfer process of the heat generated by axle-mounted brake disc during emergency braking between the axle disc, connecting piece and axle during braking and after stopping; the contact thermal resistance between wheel disc and wheel, wheel and axle, axle disc and connecting piece, connecting piece and axle are considered, then the temperature variation law of the contact position between wheel and axle, axle brake disc and axle is obtained, and the influence of this temperature variation on the contact stress of interference fit position is analyzed. The results show that the heat generated by braking makes the temperature of the contact position between wheel and axle rising to 73 ℃, while the temperature of the contact position between axle disc connector and axle rising to 216 ℃, and the highest temperature appears after parking; the braking temperature has a little influence on the contact stress at the interference fit position between wheel and axle, and it does not change the stress distribution law; while the braking temperature has a great influence on the contact stress of the interference fit position between the axle disc connector and the axle, and it obviously changes the stress distribution law.