A cutter dissembling device comprises a supporting plate, two stop units installed on the supporting plate, and an exposed structure installed on the supporting plate and located between the two stop units. When the supporting plate is operated to approach a lawn mower, different edges of a blade of the lawn mower are contacted by the two stop units, thus to prevent the unidirectional rotation of the blade. The exposed structure is utilized to correspond to a joining part of the blade of the lawn mower, so that the cutter dissembling or assembling operation can be safely performed.一種卸刀裝置,在一支撐板安裝二阻擋單元與一顯露結構,顯露結構位於二阻擋單元之間。在支撐板靠近一割草機時,二阻擋單元接觸一刀片不同的邊,阻止刀片單向轉動,以顯露結構面對刀片與割草機結合處,安全的進行卸刀或組裝作業。10‧‧‧卸刀裝置12‧‧‧握持部20‧‧‧連接結構22‧‧‧第一彎曲部24‧‧‧第二彎曲部30‧‧‧支撐板40‧‧‧阻擋單元42‧‧‧螺帽44‧‧‧直柱50‧‧‧顯露結構52‧‧‧孔60‧‧‧割草機62‧‧‧刀片64‧‧‧緊固件66‧‧‧扳手68‧‧‧套筒
