The invention discloses a multi-fluorescence channel detection system for a real-time fluorescence quantitative PCR. The multi-fluorescence channel detection system comprises fluorescence detection units, an optical fiber disc and a turntable, wherein each fluorescence detection unit comprises a light source, an excitation light filter, a dichroscope, optical fiber coupling lenses, optical fibers, a detection light filter and a photoelectric sensor, the dichroscopes enable existing excitation units and detection units to be combined to form a whole, the light emitted by the light source is sequentially subjected to filtration of the excitation light filters and coupling of the optical fiber coupling lenses and finally is emitted into a test tube through the optical fibers to excite the fluorescent substances of samples in the test tubes so as to produce fluorescent light, a part of the fluorescent light returns to the optical fiber coupling lenses through the optical fibers sequentially to be collimated, the detection light filters filter out pure fluorescent light, and the fluorescent light is finally emitted to the photoelectric sensors to perform photoelectric conversion. Multiple optical fibers are inserted into the optical fiber disc, multiple fluorescence detection units are distributed on the turntable, and fluorescence signals of multiple fluorescence channels at multiple test tube hole positions can be sequentially detected through the turntable rotating around the circle center of the optical fiber disc for one circle.