A centrifugal fan module comprising a fan housing and an impeller is provided. The fan housing includes an air inlet and a sidewall. The sidewall is pivotally disposed in the fan housing to rotate in the rotational direction relative to the fan housing. A tongue portion is formed between the sidewall and the impeller, a pressurized region is formed from the tongue portion along the rotational direction to the air outlet, the pressurized region includes a strong airflow region and the dust-discharging hole is in the strong airflow region.