Endoscope insertion part mounting mechanism and mounting method

The invention discloses an endoscope insertion part mounting mechanism and a mounting method.The endoscope insertion part mounting mechanism comprises a rotating sleeve and a mounting sleeve, an inner cavity of the rotating sleeve comprises a flange positioning section, a mounting section and a receding section, a first mounting groove and a second mounting groove are formed in the peripheral wall of the rotating sleeve, the first mounting groove is used for mounting a clamping ring, and the second mounting groove is used for mounting a second clamping ring; the second mounting groove is used for mounting a first sealing ring; a limiting block and an external connecting part are further arranged at one end of the rotating sleeve; a fixing flange is arranged at one end of the mounting sleeve, two threaded pipe via holes are formed in the end face of the fixing flange, a third mounting groove is formed in the peripheral wall of the mounting sleeve and used for mounting a second sealing ring, the mounting sleeve