A method of dynamic solving cutting force and cutting temperature in end milling was established based on steady state oblique cutting principle in order to study the distribution cutting temperature and cutting forces in process of spiral end milling. The change of cutting temperature and cutting forces of AISI1045 steel in a certain operating condition was studied. Results indicate that the maximum of Fx, Fy and Fz are 198, 40 and 90 N respectively, the deviation between calculated and measured value are 2%, 20% and 10% respectively. The maximum temperature Tmax of toolchip area appears three typical nonlinear phases of changing, among which the temperature of the first and second phase has a significant change, the maximum temperature is about 150 ℃, the deviation between calculated and measured value is 10%, which show the well agreement. Study shows that the established method can be used to investigate the thermomechanics of workpiece accurately in milling process.