As a fluorescent substance

4-methylumbelliferone（ 4-MU） is widespread in food and biochemical tests.According to the detection of 4-MU

a fluorescent substance rapid detection method based on fluorescence analysis is proposed. LED as the excitation light source

a portable and high-sensitivity fluorescent substance rapid detection system is designed and realized. Comparison calibration and experiments are implemented between the system and multifunctional microplate reader. It is found that the linearity of the designed system is 0. 997

and the detection error is less than 1. 5 % and response time is less than 0. 5 s. This research paves a reference for development of food and biochemical fluorescent substance tests device.