Abstract: On each draft element of a ring spinning frame, two pieces of short-staple roving from the roving bobbin enter into the draft mechanism to be drafted though a guide funnel in parallel, two pieces of filament are fed from the back of the front roller, and combine with two pieces of roving at front jaw respectively. The drafted two pieces of roving and filament are output from the front jaw and enter into the twisting triangle area to be twisted, and then are wound onto a yarn bobbin to produce yarn. Based on the relative position of the two pieces of roving and two pieces of filament, different yarns can be produced. Furthermore, multi-component yarn, such as core structure, wrapped structure, strand-like structure, can be produced on a ring spinning frame. The structure of yarn can be precisely determined. Special fiber yarn can be produced on traditional spinning frame.