The invention provides a vibration attenuation buffer device for a car power assembly. The device comprises a mounting base, a pressure bearing shaft, a first vibration attenuation part and a second vibration attenuation part, the mounting base is provided with a buffer cavity, the interior of the buffer cavity is provided with a vibration attenuation table with a vibration attenuation cavity, anda buffer part used for buffering instant impact borne by the vibration attenuation table, the lower end of the pressure bearing shaft is located in the vibration attenuation cavity, the upper end extends out of the mounting base, the extending-in part of the pressure bearing shaft is provided with an abut-joint plate, the vibration attenuation cavity is divided into a first cavity and a second cavity, the first vibration attenuation part is located in the first cavity and sleeves the periphery of the pressure bearing shaft, and the second vibration attenuation part is located in the second cavity. When the power assembly generates vibration, rigidity and damping are generated on positions of the first vibration attenuation part and the second vibration attenuation part, compared with theprior art, the power assembly is subjected to vibration attenuation and buffer at the same time, relative to the first vibration attenuation part, due to the fact that the movable rigidity of the second vibration attenuation part is low, the whole vibration attenuation frequency band range of the first vibration attenuation part and the second vibration attenuation part can be widened, and the vibration attenuation effect can be improved.