A surgical instrument comprises an instrument main body and a tenon-and-mortise type base. The instrument main body is provided with an external module dedicated socket for accommodating a localizer which can be positioned and tracked, in which the wall of the socket comprises a plurality of openings, the localizer transmits a positioning signal in a wireless transmission fashion, and the positioning signal includes an instrument identification code, The tenon-and-mortise type base is used for catch-holding an operating device which is fitted into the instrument main body, in which the operating device is a positioning probe, a pointed cone, a bone chisel, a bone drill or a locking instrument for surgical use.一種手術器械，包含一器械主體及一卡榫式基座，器械主體上設有一外掛式模組專用插槽，用以容置一可被定位追蹤之定位標，卡榫式基座係用以卡持嵌合於該器械主體之一操作器械。
