This model is the latest version of the comprehensive feeding thick material flat sewing machine (double needle), which uses a large vertical rotary shuttle (special rotary shuttle for thick thread) to hook the thread and a sliding rod to pick the thread. The upper and lower shafts are supported by needle roller bearings, driven by synchronous toothed belts, and lubricated by a plunger type oil pump system. Adopting the method of swinging the needle bar to press the foot and synchronously feeding the fabric teeth. The whole machine has a light and smooth transmission, low noise, high durability, and is equipped with a clutch device to protect the spinning shuttle from overload, ensuring the quality of sewn products and the safety of the spinning shuttle. This product has been improved on the basis of the 4400 model, with an increased operating space (330mmx125mm), a maximum wire thickness of 20 strands, and a needle spacing of 12mm per needle. Especially suitable for sewing car seat cushions, seat belts, airbags, etc., it can also be used for sewing large equipment such as tents, parachutes, mats, sails, etc.