The active control of the characteristics of flow around a bluff body and flow-induced vibration was numerically investigated by using the synthetic jet. Results showed that the vortex-induced vibration of the cylinder was well suppressed with the increase of the momentum coefficient of synthetic jet. As the jet position moved from the rear stagnation point to the front stagnation point

the vortex shedding mode of the cylinder wake showed the evolution of the steady state-transition state-antisymmetric 2S vortex shedding mode attached to the backflow surface of the cylinder. The two-degree-of-freedom vibration trajectory of the cylinder was in the shape of “8”

“one” in the case of complete suppression

and “crescent” in the case of partial suppression. The introduction of synthetic jet can effectively reduce the lift force on the cylinder. When the synthetic jet was located at the edge of 1/4 arc on the leeward side of the cylinder

the in-flow oscillation and cross-flow oscillation of the cylinder can be suppressed with the best suppression effect.