The application discloses a filter device. The filter device comprises: a coupling channel distinguishing part positioned between a first filter part and the second filter part, used for dividing a coupling channel between the first filter part and the second filter part into a plurality of independent coupling channels, and comprising a channel distinguishing part and at least one decoupling part, wherein the channel distinguishing part is used for dividing the coupling channel into a plurality of independent channels, and the at least one decoupling part is used for decoupling the independent channels into a plurality of independent decoupling channels; and at least one adjusting part, wherein each adjusting part in the at least one adjusting part is used for adjusting the preset coupling modes of the corresponding coupling channels, and is located in the corresponding independent coupling channels to take the axis of the corresponding independent coupling channel as a first straightline, and each adjusting part in the at least one adjusting part is located in a corresponding projection area.