The invention discloses a high efficiency large power LED fiber light source comprising an aluminium alloy cavity; the aluminium alloy cavity is a structure with large left end caliber and a small right end caliber; a radiation pedestal, a lens fixing cylinder, an acrylic non spherical lens and a full transparent Teflon sleeve pipe are arranged in sequence from left to right in the aluminium alloy cavity; the right end of the full transparent Teflon sleeve pipe is connected with a plastic fiber, and partial of a plastic fiber naked core inserts into the full transparent Teflon sleeve pipe; the full transparent Teflon sleeve pipe is arranged in the right end, with the small caliber, of the aluminium alloy cavity; a large power LED lamp bead and a cone lens are arranged in the lens fixing cylinder. End faces and side faces are simultaneously coupled so as to couple a large light spot into the plastic fiber with the small diameter, thus greatly improving LED light and plastic fiber coupling efficiency; the high efficiency large power LED fiber light source is small in size, convenient in dismounting, high in luminous energy utilization rate and optical power, and can be widely applied to illumination light source, fluorescence and radiation dose detection excitation light source fields.