The invention belongs to the field of wave-suppressing technology research and particularly relates to a plate type wave-suppressing device easy to dismount. The plate type wave-suppressing device easy to dismount comprises a support and a double-sheet type wave-suppressing plate arranged on the support. The support comprises a pair of parallel bottom beams, front support bodies and rear support bodies, wherein the front support bodies and the rear support bodies are arranged on the bottom beams in a matched mode. The front support body and the rear support body on each bottom beam are matched in a hinged mode. The end, opposite to the hinged end, of each front support body is detachably connected with a set of convex lugs arranged on the corresponding bottom beam through a bolt. The end, opposite to the hinged end, of each rear support body is in sliding fit with the inner side of the corresponding bottom beam. The double-sheet type wave-suppressing plate is trapezoidal and is composed of two symmetrical wave-suppressing sheets with narrow ends. The front support bodies and the rear support bodies are sleeved with the double-sheet type wave-suppressing plate, and the narrow ends of the double-sheet type wave-suppressing plate are fastened through a hoop. The plate type wave-suppressing device easy to dismount is simple in structure; and replacement and dip angle adjustment of the wave-suppressing plate are convenient, so that the plate type wave-suppressing device easy to dismount is applicable within a wider water depth and wave height range and has a good wave-suppressing effect.