The figure shows the frequency domain diagram of bearing 1 and bearing 3 when root crack and raceway fault occur simultaneously. The main frequency components in figure (a) are: double frequency 2𝑓b (141hz) of rolling element fault, 𝑓o (107.3hz) of rolling bearing outer raceway fault And the meshing frequency of faulty gear 𝑓m (570.4hz). The main frequency components in figure (b) are: double frequency 2𝑓b (141hz) of rolling element fault and other frequency multiplication, frequenc 𝑓o (107.3hz) of outer raceway fault frequency of bearing 1, and 2 𝑓o3 (85.25hz) of outer raceway fault frequency of bearing 3 the meshing frequency of the fault gear is 𝑓m (570.4hz).