A handheld end of an endoscope, comprising a housing, an insertion end positioning assembly and a self-locking assembly, wherein the self-locking assembly is hinged to the housing; the housing comprises an insertion port, and a protective shell; the insertion end positioning assembly comprises a positioning member, a first positioning nut, a threaded steel tube, a through hole, a fixing member and a locking member; the positioning member is inserted into the insertion port; the threaded steel tube is in threaded fit with the first positioning nut; and the first positioning nut is fixed in the positioning member; the fixing member is fit with the through hole to abut against the threaded steel tube; an inner bottom of the locking member is provided with a straight clamping slot, and an inner wall of the locking member is provided with an internal thread; a tail end of the positioning member is provided with a straight fixing block; and the straight fixing block is fit with the straight clamping slot; and the protective shell is provided outside the insertion port, and the protective shell is fixedly connected to the insertion port; and the protective shell is provided with an external thread, and the external thread of the protective shell is fit with the internal thread of the locking member, wherein the positioning member is provided with a limiting slot; the insertion end positioning assembly further comprises a stop piece, and the stop piece is provided in the limiting slot; a diameter of the stop piece is greater than a diameter of the insertion port; the fixing member comprises a second nut and a fixing screw; the second nut is fixed to the through hole; and the fixing screw is in threaded fit with the second nut. the housing comprises an insertion port, and a protective shell; the insertion end positioning assembly comprises a positioning member, a first positioning nut, a threaded steel tube, a through hole, a fixing member and a locking member; the positioning member is inserted into the insertion port; the threaded steel tube is in threaded fit with the first positioning nut; and the first positioning nut is fixed in the positioning member; the fixing member is fit with the through hole to abut against the threaded steel tube; an inner bottom of the locking member is provided with a straight clamping slot, and an inner wall of the locking member is provided with an internal thread; a tail end of the positioning member is provided with a straight fixing block; and the straight fixing block is fit with the straight clamping slot; and the protective shell is provided outside the insertion port, and the protective shell is fixedly connected to the insertion port; and the protective shell is provided with an external thread, and the external thread of the protective shell is fit with the internal thread of the locking member, wherein the positioning member is provided with a limiting slot; the insertion end positioning assembly further comprises a stop piece, and the stop piece is provided in the limiting slot; a diameter of the stop piece is greater than a diameter of the insertion port; the fixing member comprises a second nut and a fixing screw; the second nut is fixed to the through hole; and the fixing screw is in threaded fit with the second nut.