The invention relates to a high-speed response electromagnetic valve type fuel injector for a motorcycle, in particular relating to a fuel injector which comprises a shell, a limit pipe, an electromagnetic coil, a return spring, a valve plug, a valve seat, seal steel balls, a fuel injection pore plate and a flux sleeve, wherein the shell is internally provided with a main shaft of an integrated type turbular structure; the small end inner bore of the main shaft is sequentially provided with the limit pipe and the return spring; the large end inner bore of the main shaft is sequentially provided with the valve plug and the valve seat; the small end and large end of the main shaft are transitionally integrated at the end surface coordination part of the main shaft and the valve plug; the high-speed response electromagnetic valve type fuel injector provided by the invention is also provided with a rotary fuel cap capable of rotating by 180 degrees; and one side of the shell is provided with a mounting hole,and the other side of the shell is provided with a locating pin. According to the invention, the main shaft and a magnectic shield are designed to be integrated, not only can the magnetic flux of an electromagnetic return circuit be increased effectively, but also the residual magnetism of the electromagnetic return circuit is reduced, and the suction force of the valve plug is improved greatly, thus the resoponse speed of the fuel injector is improved, and the high-speed response electromagnetic valve type fuel injector provided by the invention has the advantages of simple structure and low manufacturing cost, and can be adaptive to the mounting requirement of the narrow space of the motorcycle.