In order to explore the flow interaction between the oscillating jet of the fluidic oscillator and the crossflow with different crossflow Mach numbers， the transient flow fileds are numerically studied under the nozzle pressure ratio （NPR） of 1.5，3.0 and the crossflow Mach numbers of 0， 0.2， 0.4， 0.6， 0.8. The effects of crossflow on the internal oscillation features of the fluidic oscillator， as well as the downstream flow interaction characteristics between the oscillating jet and the crossflow， are analyzed. The results show that when NPR=1.5， the Mach number at the secondary throat of the fluidic oscillator is less than 1， the disturbance from the crossflow will affect the internal oscillation frequency of the fluid oscillator； when NPR=3， since the Mach number at the secondary throat of the fluidic oscillator is greater than 1， the disturbance from the crossflow will be effectively isolated. When NPR=3 and the crossflow Ma is 0.2， there are two pairs vortices of downstream flow fields with opposite rotating directions， among which the upper one is the vortex pair induced by the oscillating jet， and the lower one is the horseshoe vortex pair； when the crossflow Mach number exceeds 0.4， there is only a pair of vortices in the downstream space， and the vortex can effectively divert the low-energy flow at the center of the cross-section and make the velocity profile of the boundry layer fuller， shape factor smaller； with the increase of the crossflow Mach number， the momentum ratio of the jet to the crossflow， the penetration depth of the jet and the spanwise influence range of the jet decrease.