For the dissimilar joint of continuous drive friction welding, an analytical solution was proposed to predict the steady-state average temperature in the plastic region, which was resorted to the distribution coefficient of welding heat. The steady-state average temperature in the plastic region of two dissimilar joint TC4/TC17 and TC11/TC17 were calculated in the following cases: constant rotation speed but different welding pressures and constant welding pressure but different rotation speeds. The calculated average temperature was compared with the experimental temperature data. The results show that when the rotational speed is holding constant, the average temperature decreased with the increasing welding pressures, while when the welding pressure is holding constant, the average temperature increased with the increasing rotational speeds. When the welding parameter is holding constant, the average temperature of the TC17 side of dissimilar joints are always lower than that of the other side, whether TC4/TC17 or TC11/TC17 joint. The calculated temperature and the actual temperature agree well and the difference between them is less than 7% which shows the accuracy of the analytical solution.