The invention discloses a polyester yarn creeling yarn-covering dyeing method. The polyester yarn creeling yarn-covering dyeing method comprises the following steps: (1) yarn loosening: selecting a yarn loosening bobbin, sleeving the yarn loosening bobbin with a cloth barrel, loosening billet yarns, and then winding around the exterior of the cloth barrel on the yarn loosening bobbin to form a yarn loosening spool, wherein the two ends of the cloth barrel are protruded out of the two ends of the yarn loosening bobbin respectively; (2) spool replacement: turning the two ends of the cloth barrel on the yarn loosening spool after winding in the step (1) respectively to cover yarns on the yarn loosening spool, taking out the yarn loosening bobbin of the yarn loosening spool, and replacing with a dyeing bobbin to form a dyeing spool, wherein the outer diameter of the dyeing bobbin is smaller than the diameter of the yarn loosening bobbin; (3) dyeing: dyeing the dyeing spool obtained in the step (2). The polyester yarn creeling yarn-covering dyeing method can effectively solve the problem about quality of dyeing colored loops from polyester yarns, so that the production period and the production efficiency are guaranteed.