Disclosed are a folding wheel and a portable appliance. The folding wheel includes: a wheel body, wherein the wheel body include two wheel plates that can be spliced with each other, and a notched area is formed therebetween when the two wheel plates are spliced with each other; a first connecting element disposed in the notched area; a first slide rail mechanism, at least part of which is disposed on the first connecting element, and remaining parts of which are disposed on respective wheel plates, wherein the first slide rail mechanism includes a first rail groove and a first rotating shaft inserted into the first rail groove, such that the two wheel plates can be spliced with or separated from each other along the first rail groove via the first rotating shaft, and can be flipped relative to the first connecting element via the first rotating shaft; the folding wheel is foldable, wherein when the two wheel plates are pulled away from each other, the two wheel plates slide away from each other along the first rail groove. The two wheels may be flipped, wherein when the two wheel plates are folded towards each other, the portable appliance with reduced folded size facilitates the user to pack or carry.