The invention belongs to the field of yarn guide and needle feeding devices, and particularly discloses a knitwear processing and thread feeding device. The device comprises a base, a support, a motor, a conveying belt, a controller, an air cylinder, a nut, a conveying wheel and a spool, the conveying wheel is in a circular truncated cone shape, and the support is fixedly connected with the base;the motor is fixed onto the base, a rotation rod is connected to the output shaft of the motor, and the rotation rod is connected with one end of the conveying wheel; a threaded rod is fixedly connected to the other end of the conveying wheel; the threaded rod is matched with the nut in a threaded mode, the conveying wheel drives the spool to rotate through the conveying belt, and a conveying roller is rotatably connected onto a rack; an infrared emitter is arranged on the eccentric portion of one end of the conveying roller, an infrared receiver which can receive infrared rays is arranged onthe support, and the infrared receiver is electrically connected with the controller; the controller is connected with the air cylinder, and a fixing part which can fix the nut is arranged at the freeend of an air cylinder piston. According to the knitwear processing and thread feeding device, the tightness degree in thread feeding of knitwear can be automatically adjusted, and the adverse effecton knitwear processing is avoided.