With the growth of the level of China’s textile industry and exports, increasing demand for shuttleless looms. Shuttle loom technology development watching from abroad, have undergone tremendous changes in the mechanical and electrical integration, speed, and selection technology, compared with foreign and domestic equipment, there is a big gap, improve, develop and improve domestic non-woven the performance of the machine is imminent. Shuttleless looms one of the most important models rapier weft selection device is a key part of the rapier. According to actual needs, design a stepper motor driven weft selector dial control weft selection device, applied to specific rapier, this design is completely different from the linear motor control of the company’s existing rapier selected latitude refers designs. Loom customers for annual savings of tens of thousands of yarn cost, both to improve the sales of the company’s rapier, but also improve the performance of the rapier. This article from the mechanical parts, motor parts and electrical parts of three study new weft selection device. The mechanical part according to the location and characteristics of this weft selection device, define the action of this device is driven by a stepper motor weft weft selection plate to control. The connection part of the use of belt connection. Thus the mechanical part of the important parts made detailed design calculations, given the size of some parts of machinery.