The invention discloses a flexible shaft telescopic control mechanism of a dredging machine and the dredging machine, wherein the flexible shaft telescopic control mechanism comprises a fixed bearing seat, a movable bearing seat and an operating handle; a first bearing group and a second bearing group, which are matched with a flexible shaft, are arranged between the fixed bearing seat and the movable bearing seat; and the operating handle is used for controlling the corresponding bearing groups to be matched with the flexible shaft. According to the invention, under the precondition of keeping a rotating direction of the flexible shaft unchanged, the bearing group, which is to be matched with the flexible shaft, can be conveniently selected by rotating the operating handle, so that the flexible shaft can be conveniently controlled to move forwards or backwards; and since the rotating direction of the flexible shaft is kept unchanged, foreign matters at the end are prevented from getting fallen easily when the flexible shaft moves backwards. Neither of the bearing groups is matched with the flexible shaft when the movable bearing seat, which is controlled by virtue of the operating handle, is kept on a balanced position, and at the same time, the flexible shaft can rotate in place and cannot move forwards or backwards.