A data transmission cable includes a first wire and a second wire adjacent to each other, each of the first wire and the second wire has a central conductor and a cover layer enclosing the conductor. The conductor has an outer diameter in the range of 28 to 31 AWG, and when the outer diameter of the conductor is 28 AWG, the center distance between the first and second wires is defined between 0.51 mm to 0.75 mm; when the outer diameter of the conductor is 29 AWG, the center distance between the first and second wires is set between 0.38 mm to 0.75 mm; when the outer diameter of the conductor is 30 to 31 AWG, the center distance between the first and second wires is set between 0.38 mm to 0.62 mm.