The invention discloses a construction machinery device for improving the exhaust sound quality. The construction machinery device comprises a fixed-frequency sound adjusting device and a variable-frequency sound adjusting device arranged on the inner wall of a tube, the fixed-frequency sound adjusting device comprises a throat opening with the diameter contracted to the inner wall of the tube anda vibration film arranged in the throat opening, the variable-frequency sound adjusting device comprises a rotatable impeller, and the variable-frequency sound adjusting device is fixed at the position, at the back portion of the air flow direction in the tube, of the fixed-frequency sound adjusting device so that the air flow firstly passes through the fixed-frequency sound adjusting device andthen passes through the variable-frequency sound adjusting device. The construction machinery device uses the vibration film structure of the air flow impact imitation sound band to produce the fixed-frequency medium frequency, the proportion of the medium-frequency sound of the exhaust sound is improved, the impeller is driven to rotate by using the air flow, the blade cuts the air flow to produce the variable-frequency wide frequency sound related to the air flow speed, the optimization target is determined according to the host exhaust sound and user demand, the imitation sound band vibration film fixed frequency and the number of the wind turbine blade are adjusted, the sounding frequency is adjusted, and the fact that the exhaust sound quality is significantly improved under the low-pressure resistance condition is achieved.