An adjustable endoscope fixing device comprises a tail bed, a three-way connector and a locking screw； an outer wall surface of a straight column section of the tail bed is provided with a rectangular slot； and an outer wall surface of a first connecting end of the three-way connector is provided with a locking structure, and the straight column section of the tail bed is connected to the first connecting end of the three-way connector, and the tail bed is fixed to the three-way connector by the locking structure.
