A multi-channel fluorescence measuring optical system and a multi-channel fluorescence sample analyzer using the optical system are provided. The multi-channel fluorescence measuring optical system, which irradiates light onto a plurality of sample channels and detecting fluorescence radiated from samples, includes: a light source; an integrator for giving the light irradiated from the light source a uniform intensity distribution; a sample holder having a plurality of sample channels on which the samples are mounted, wherein the samples are exited by the light emitted from the integrator; and a beam splitter between the integrator and the sample holder for dividing the incident light in a predetermined ratio. Since the light intensities of fluorescence images are detected using optical fiber bundles and photodiodes, the manufacturing cost can be greatly reduced, and the optical system can be miniaturized.