An endoscope, an optical machine connecting device and a method for modifying a two-dimensional endoscope system. The endoscope comprises an optical machine connecting unit, an insert tube (1), and a first lens (3) and a second lens (4) integrated into the insert tube (1). The optical machine connecting unit comprises an optical deflection assembly (5) and a connecting assembly (7). The optical deflection assembly (5) is used for changing a space between optical axes of a first light beam (021) and a second light beam (031) received and projected by the first lens (3) and the second lens (4), so as to match an image sensor (012) arranged in a camera connector (01) of the two-dimensional endoscope system. The connecting assembly (7) is used for forming a butt joint between the endoscope and the camera connector (01), and is used for limiting the space between the optical deflection assembly (5) and the image sensor (012). The optical machine connecting device corresponds to the optical machine connecting unit in the endoscope. In the modifying method, the endoscope is used for upgrading an existing two-dimensional endoscope system into a three-dimensional endoscope system by means of a selection step (S1), a butt joint limiting step (S2) and the steps of upgrading and replacing a read end processing device (S3 and S4).Linvention concerne un endoscope, un dispositif de connexion de machine optique et un procédé de modification dun système endoscopique bidimensionnel. Lendoscope comprend une unité de connexion de machine optique, un tube dinsertion (1), ainsi quune première lentille (3) et une seconde lentille (4) intégrées dans le tube dinsertion (1). Lunité de connexion de machine optique comprend un ensemble de déviation optique (5) et un ensemble de connexion (7). Lensemble de déviation optique (5) est utilisé pour changer un espace entre les axes optiques dun premier faisceau lumineux (021) et dun second faisceau lumineux (031) reçus et projetés par la première le
