Multi-channel fluorescence detection system and detection method

The invention discloses a multichannel fluorescence detection system which comprises a fixed seat and an objective lens, the fixed seat is provided with at least two fluorescence detection channels for performing fluorescence detection on a sample to be detected, and a reflector is arranged between the objective lens and the fixed seat; the reflecting mirror is used for reflecting the exciting light generated by the fluorescence detection channel directly facing the reflecting surface of the reflecting mirror, so that the reflected exciting light passes through the objective lens to detect the sample to be detected, and is used for reflecting the detection light generated by the sample to be detected into the fluorescence detection channel after passing through the objective lens; the fixed seat is provided with a fluorescence detection switching mechanism which is used for driving the reflecting mirror to rotate so as to enable the reflecting surface of the reflecting mirror to sequentially face different fl