Abstract: K418 superalloy/42CrMo dissimilar metals were welded by continuous driven friction welding.The microstructure and element content of the welded joint were analyzed.The results show that the main elements of K418 diffuse to 42CrMo, the carbon element of 42CrMo diffuses to K418, the secondary friction interface is formed near the weld zone at the side of K418, a banded carbide forms after welding, and the K418 between banded carbide and the weld is recrystallized.