The invention discloses an air concentration measuring system and method based on a super-continuum spectrum light source. The air concentration measuring system provided by the invention comprises a super-continuum spectrum light source, an optical isolator, an optical switch, an air chamber, an optical signal calibration device, a tunable optical filter and a photoelectric detector which are in series connection with each other in sequence by means of optical fiber cables, as well as a data collecting system. The photoelectric detector is connected with the data collecting system by means of data wires. The light emitted by the super-continuum spectrum light source reaches the optical switch through the optical isolator and reaches the air chamber through the optical switch, the optical signals in the air chamber enter into the optical signal calibration device, the calibrated optical signals are demodulated by the tunable optical filter, weak optical signals are converted by the photoelectric detector into electric signals, and is the electrical signals are input into the data collecting system. Compared with the prior art, the system has the advantages that the spectrum of the light source has good evenness and stability. In addition, the invention is capable of testing multiple gases and implementing concentration testing and category identification on multiple gases simultaneously.