Abstract: On the basis of analyzing the principle of high speed cold rolling forming, the mathematical model of thermo-mechanical coupling was established. Combining static and dynamic compression tests with different strain rates at room temperature or high temperature and the application of Johnson-Cook flow stress formula, the constitutive model of 40Cr quenched and tempered steel was established. Using finite element software, high speed cold rolling forming of 40Cr quenched and tempered steel was simulated. In considering the combined effect of work hardening and dynamic softening, the distribution of the stress, strain and temperature were obtained to discuss the forming reasons for thermo-mechanical coupling in cold roll process, and the influence of forming rate on thermal effect. Finally, verification test was carried out. The results show that the temperature distribution and equivalent plastic strain of the workpiece were not evenly distributed. In intense strain region, the equivalent plastic strain was relatively large and the temperature rising was high. In hard deformation zone, the equivalent plastic strain was small and temperature rising was low. The experimental results proved the correctness of the simulation.