Method for knitting and forming weft-knitted fabric with varying thickness by flat knitting machine and weft-knitted fabric thereof

A method for knitting and forming a weft-knitted fabric with varying thickness by a flat knitting machine, the method comprising steps of:

• driving the flat knitting machine to knit a basic structure by at least one of two needle beds of the flat knitting machine, wherein the basic structure is selected from a single-layer fabric or a double-layer fabric;
• and
• controlling the two needle beds on the flat knitting machine to knit a three-dimensional structure connected with the basic structure, wherein a thickness of the three-dimensional structure is greater than a thickness of the basic structure, the three-dimensional structure comprises two surface layer portions and a supporting portion connected with the two surface layer portions and located between the two surface layer portions, wherein the flat knitting machine is controlled to be temporarily suspended from feeding a supporting yarn at a junction between the three-dimensional structure and the basic structure, thus the junction without the supporting portion, and the supporting yarn is fed to form the supporting portion after the two surface layer portions are knitted with a plurality of stitches, and wherein during a process of knitting the supporting portion, the flat knitting machine drives two knock-over bits of the two needle beds to displace and change a size of a mouth of the flat knitting machine, and a height of the supporting portion is not a fixed value.