The present invention discloses a transposition mechanism of North Finder in the teaching experiment of optical fiber gyroscope. The transposition mechanism comprises a spectrometer (3), and is characterized by comprising a bracket (1), a tray (2), a dial (4), and a transparent indicating pointer (15); the bracket (1) consists of a right support plate (11), a left support plate (12), a bottom plate (13), a right bearing component (14), a left bearing component (19), an A bracket (16), a B bracket (17), a rotating shaft (18) and the transparent indicating pointer (15). The transposition mechanism has the following advantages: (1), the transposition mechanism has the functions of rotating and adjusting the horizontal shaft and the vertical shaft; (2) the transposition mechanism has a large size and high rigidity, and facilitates the installation of the optical fiber gyroscope with large size; (3) the whole body is made of aluminum alloy and other light materials, and thus being wholly light; (4) the level transposition rule and the observation window facilitate the operation and observation of students; and (6) the whole structure is wide, facilitates the operation, observation and manual adjustment, and has an attractive appearance.