The invention discloses a special 3D upper knitting mechanism which includes a left adjustable head, a right adjustable head, a right seaming cam, a left seaming cam, a middle ling, a cap and heel sewing knife and a cap and heel blocking knife (13) that form a single knitting ring system; a guide plate, a needle drum and knitting needles form a feeding system; a lower steel ring, a lower puller I,a lower puller II, a middle steel ring, the left adjustable head, the right adjustable head, the right seaming cam, the left seaming cam and the middle ling form a common knitting system; the lower steel ring, a forward needle selector, a reverse needle selector, the middle steel ring, the left adjustable head, the right adjustable head, the right seaming cam, the left seaming cam and the middleling form a loop selection system. According to the invention, the problems in the knitting of the conventional flat knitting machine such as low speed, deficiency of special deformation of human foottype in upper fabric, poor shoe type appearance are thoroughly solved; the product benefit is 200% of that of a flat knitting machine, and is improved by 30% compared with that of a hosiery machine refitted upper machine; meanwhile, the discharge stock blank pull rate and the rate of certified products are greatly improved, and the upper blank is easy to size.