The invention relates to a composite turning device for an outer pipe of a fast suturing device for medical operations and belongs to the field of medical instrument machining devices. The composite turning device comprises a feeding base, a discharging base, a material conveying pneumatic cylinder, a material conveying clamping base, a material collecting base, a main shaft clamping base, a left side knife holder, a right side knife holder, an axial movement table, a power device and a material collecting cylinder; the material conveying pneumatic cylinder is arranged on the front side of the feeding base and is connected with the material conveying clamping base which is installed on a material conveying slide rail; a left side axial movement table and a right side axial movement table on the two sides of the main shaft clamping base of the middle portion of the axial movable table are provided with the left side knife holder and the right side knife holder correspondingly; the left side knife holder and the right side knife holder are both connected with the power device; the material collecting base is arranged on the right side of the axial movement table and is installed on a material collecting slide rail; and the discharging base is arranged behind the left side of the axial movement table. The composite turning device is simple in structure and fast in production turning, the one-machine two-turning action is completed, manual work is not needed for feeding and discharging, and therefore the manual operation is reduced, the labor cost is saved, and the producing and machining efficiency is improved.