The invention belongs to the field of clothes and particularly relates to a knitting method of an integrally-formed seamless sock. The method includes steps: providing a design sample of the integrally-formed seamless sock; by computer simulation, accurately calculating the total length of a yarn for knitting of the integrally-formed seamless sock and yarn areas corresponding to parts of the integrally-formed seamless sock; providing an integral yarn according to a computer simulation result, wherein the integral yarn is a corn spun yarn and comprises an integral core yarn and a coating fiberlayer which covers the surface of the core yarn, and the coating fiber layer is not completely identical on different parts of the integrally-formed seamless sock. The yarn is knitted into the integrally-formed seamless sock by a hosiery knitter.