The invention relates to a yarn guide rod assembly of a single-tube yarn feeder. The yarn guide rod assembly is characterized by comprising a yarn guide rod and a yarn guide ring, wherein the yarn guide rod is of a flat sheet shape; a mounting hole is formed in one end of the yarn guide rod; a plurality of yarn coil mounting grooves are uniformly distributed in the yarn guide rod along the length direction; the yarn guide ring is assembled in the yarn coil mounting grooves in a detachable manner; and a yarn guide hole is formed in the center of the yarn guide ring. The yarn guide rod assembly of the single-tube yarn feeder is compact in structure and reasonable in design, can provide smooth and block-free guidance to yarns and reduce a condition that the yarns are broken, so that the working efficiency and the product quality are improved.