The invention provides a round pipe cutting and clamping system. The round pipe cutting and clamping system comprises a motor, a clamping module connected with the motor, a core inserting module, a support module for fixing the core inserting module, and a tail base module, wherein the clamping module comprises a positioning column; workpieces are fixed between the positioning column and the coreinserting module; the support module comprises a magnet; and the magnet absorbs the core inserting module to press the workpieces. During loading, the workpieces are directly and flatly placed in a hole groove of an emptying module; the motor drives the core inserting module to insert in the workpieces to push the workpieces to axially move until the workpieces are inserted in the shaft end of thepositioning column of the clamping module and are axially positioned by a shaft shoulder of the positioning column; the emptying module is provided with the magnet for absorbing the core inserting module to press the workpieces; and after the cutting is finished, the tail base module drives a cartridge to retreat to a loading station, and a pneumatic clamping jaw loosens the workpieces for directunloading.