The invention relates to a bicycle, in particular to a portable folding bicycle. The invention provides the following technical scheme that the portable folding bicycle comprises a bicycle frame, a cock, a front wheel, a back wheel and a seat cushion, wherein the cock is connected with the bicycle frame, the seat cushion is arranged on the bicycle frame, the cock and the bicycle frame are connected through a connecting rod, and the other end, opposite to the connecting end with the cock, of the connecting frame is connected with the bicycle frame through a turning hinging element capable of enabling the connecting rod to turn along any one side in the transverse direction of the bicycle frame. Through the adoption of the technical scheme, the invention provides the portable folding bicycle with the advantages that the size after the folding is small, portability and easy carrying are realized, and the structure is simple.