Bio-aerosols are closely related to environment quality and human health. Aerosol detection technology with optical measurement method, which is rapid, nondestructive and sensitive, becomes to the mainstream of research. So far, there is no national standard about the evaluation and calibration method to the detection system. Based on the measurement of intrinsic fluorescence, a set of bio-aerosol detection equipment including virus aerosols is developed, with which a method of calibration is proposed using tryptophan as the target. The experimental results show a good linear response between the detection equipment to tryptophan aerosol with an excellent correlation (R2≥0.99), the sensitivity of 4000 L-1. The research demonstrates the reliability of the bio-aerosol fluorescence detection by measuring the content of tryptophan. Further more, the feasibility of prejudgment to the species of bio-aerosol particles with the multi-channel fluorescence detection technology is discussed.