Massive dust of exhausted airflow easily diffuses to the industrial square while hoisting shaft is used as return shaft in the retrograde ventilation, and certainly there is a problem of dust scattering and noise exceeding standard. In order to solve the problem, the coupled technology of dedusting and noise reduction in airshaft outlet was investigated and the device with the function of Dedusting and noise Reduction （DR） was originated. The device is named as DR diffuser, which comprehensively utilizes mechanisms of inertia-gravity dedusting and absorption-insulation sound. The DR diffuser has been applied to Xingdong Coal Mine, and the testing results show that： a. the resistance of DR diffuser is lower than 60 Pa; b. the noise level reaches to 49.2 dB（A） ; c. the dedusting efficiency of above 50 μm is higher than 85 % ; d. dynamic pressure recovered from the outlet of main fan is larger than 50 Pa. The above measured data illustrates that comprehensive benefit of the DR diffuser is good, and the device is worth of applying to engineering site.