The invention relates to a cloth cutting device capable of automatically cutting cloth. The cloth cutting device comprises a base, a first support, a second support and a third support, wherein the first support and the second support are vertically arranged on the upper end face of the base, and the third support is arranged at the upper ends of the first support and the second support. A cutting cylinder is arranged on the third support, a telescopic end of the cutting cylinder is connected with a blade holder, a cutting blade and a guide post are arranged on the blade holder, one end of the guide post is connected with the blade holder, the other end of the guide post penetrates the third support and guides lifting of the blade holder, a pressing mechanism is further arranged on the third support, lifts up and down and is used for pressing cloth, and a cutting notch matched with the cutting blade is formed in the base. When the cloth is cut, the cutting cylinder drives the blade holder and the cutting blade on the blade holder to descend, the cutting blade is matched with the cutting notch to cut the cloth, the pressing mechanism descends to press the cloth in the cutting process, so that the cloth is effectively prevented from turning upwards in the cutting process, and cutting precision of the cloth is ensured.