It is primary important to obtain the active acoustic characteristic of the bubble before studying the active acoustic detection and the sound wave transmits in the ship wake.The reflection and the refraction of the sound wave at the boundary of the air and the water together with the scattering characteristic of the bubble under the forced vibration were studied,and the active acoustic characteristic model of the bubble in the ship wake was created then.The finite element analysis was applied to the model of the bubble to obtain the accurate resonant frequency of it,the result of which was used to prove the correction of the model of the bubble when compared to the theoretical frequency of it.