The invention relates to the field of mechanical arms, in particular to a mechanical finger adopting a paper folding structure for transmission. The mechanical finger comprises a plurality of knuckleswhich are sequentially hinged to one another, and a knuckle driving device for controlling the knuckles to bend and stretch. The knuckle driving device is of a paper folding type linkage structure which is composed of a paper folding structure provided with multiple folding marks joining in one point, a paper folding page is formed between every adjacent folding marks, every two adjacent paper folding pages are hinged through folding marks, and the multiple paper folding pages are sequentially hinged and linked. According to the technical scheme, the angle between two adjacent knuckles is changed by controlling the rotating of the two adjacent knuckles through a driving plate and a connecting plate hinged to the driving plate. The mechanical finger is simple in structure, and quick to torespond to holding actions.