The invention discloses a straw bag knitting machine. The machine comprises a machine body, a material cavity which is provided with a forward opening and used for placing straw or rice straw is formed in the machine body, a push plate is arranged in the material cavity in a sliding manner, the right end face of the push plate is fixedly provided with a telescopic spring with the right end fixedlyconnected with the right end wall of the material cavity, a guide sliding groove with a downward opening is formed in the lower side of the material cavity in a communication manner, the lower end face of the push plate is fixedly provided with a guide sliding block with the lower end extending into the guide sliding groove, the upper side of the material cavity is provided with a push groove with a downward opening in a communication manner, the upper end of the push plate extends into the push groove, a sudden stop safety device is arranged on the upper side of the push groove, and a conveying cavity is formed in the left side of the material cavity in a communication manner. The knitting machine is high in whole device linkage, energy-saving, environment-friendly, high in automation degree, and capable of reducing manual participation and manufacturing cost, and through a material lacking sudden stop device, straw bags are complete, well-balanced and flat.