A method of generating hollow beam by incoherent monochromatic light emitting diode (LED) light source and multimode fiber is proposed. It is demonstrated that the hollow beam can be obtained by coupling a LED light source into a multimode fiber with a suitable incident angle. The transmission path of beam in multimode fiber and the mechanism of producing hollow beam are analyzed. The simulation model is set up by software Zemax. The experimental system generating hollow beam by LED and multimode fiber is compared with a laser source. The results show that the uniformity of hollow beam obtained by using LED light source is better.