The invention provides an external cloth collection device for a computerized flat knitting machine. The external cloth collection device comprises a cloth roller, a cloth roller clamping device, a cloth roller transmission device and a drive device. The cloth roller clamping device and the cloth roller transmission device are arranged on the two ends in the length direction of the cloth roller; the cloth roller clamping device is installed on a left wall plate of a rack via a left shaft seat box; the cloth roller clamping device is installed in the left shaft seat box, with one end being connected to the cloth roller after penetrating the box wall of one side of the left shaft seat box; the cloth roller transmission device is fixedly installed on a right wall plate of the rack via a right shaft seat box and is installed on the right shaft seat box, one end of the cloth roller transmission device being in transmission connection with the cloth roller and the other end being connected with the drive device arranged in the right shaft seat box; the cloth roller transmission device provides power for the rotation of the cloth roller via the drive device; the cloth roller clamping device enables rapid mounting and dismounting of the cloth roller. The external cloth collection device is wide in application range and facilitates rapid arrangement of knitted cloth; the modification is convenient, the cost is low, assembly and disassembly are convenient and the production efficiency is increased.