The invention discloses a fluorescent optical fiber temperature measurement optical system and relates to the field of optical fiber sensing. The system comprises an excitation light source, optical fibers and a photoelectric detection unit. The system is characterized by also comprising double-clad optical fibers, a fluorescent probe and an optical fiber coupler, wherein the fluorescent probe isarranged at first ends of the double-clad optical fibers; the excitation light source is arranged at one side of second ends of the double-clad optical fibers and used for transmitting excitation lights and coupling the excitation lights into single-mode cores; the double-clad optical fibers are connected with the first ends of the optical fibers through the optical fiber coupler; and the photoelectric detection unit is connected with the second ends of the optical fibers. The double-clad optical fibers of the fluorescent optical fiber temperature measurement optical system has the characteristics of high quality of light beams of the excitation light source and isotropy of fluorescent light serving as received light, so that transmitting and receiving ends of the system have excellent coupling and receiving characteristics.