The invention provides a full-automatic pipe cutting machine comprising a frame, and a charging device, a feeding device, a cutting device, a measuring device and a control device which are sequentially arranged on the frame horizontally; the cutting device comprises a cutter holder which is arranged on the frame, a plurality of first motors which are lined horizontally along a longitudinal direction and can be arranged on the cutter holder by moving up and down, a first cylinder which is connected with and drives each first motor to move up and down synchronously, a circular saw blade which is arranged on the output shaft of each first motor, a second motor which is in transmission connection with the input shaft of each first motor through a first transmission mechanism, and a bearing piece which is arranged on the tool rest below each circular saw blade and is used for bearing a pipe at a cut part; and the measuring device comprises a guide rail which is horizontally arranged on the frame, a slide frame which is movably arranged on the guide rail, a driving mechanism which is connected with and drives the slide frame to move along the guide rail, a pipe baffle which is arranged on the slide frame and a first pipe clamping mechanism which is horizontally arranged on the slide frame along the longitudinal direction. According to the full-automatic pipe cutting machine, more than one pipe can be cut at one time, and the machine has the advantages of high cutting efficiency, good cutting quality and the like.