A folding machine for folding fiber products and fiber products formed and stacked thereby are disclosed. The folding machine includes two folding devices, each of which includes a cutting device, a delivery wheel, a folding-line wheel, a platen wheel, and a folding wheel. The cutting device cuts the fiber product and transports the cut fiber product to the delivery wheel. The folding-line wheel is adjacent to the delivery wheel for making a first folding line on the fiber product carried by the delivery wheel, and then the platen wheel folds the fiber product along the first folding line. Subsequently, the once-folded fiber product is transported to the folding wheel. The folding wheels of the two folding devices are adjacent to each other and are used to fold the fiber product passing therethrough for a second time, and thus fiber products with three folds are formed.