A microdroplet measurement and control system is designed and realized. Parameters such as the stability of droplet and biological activity are studied

cultivate and test on microdroplet（ microorganisms

bacteria

etc.） in microfluidic chip based on the droplet microfluidic technology. The parameters of different droplets are detected through absorbance detection and fluorescence detection methods. The overall design of the system includes the laser-induced fluorescence detector based on photomultiplier tubes and the absorbancy detector based on the photocell and microdroplet manipulation. The experimental results show that in the malachite green solution testing experiments measurement range of optical density（ OD） value is 0 ～ 4. 0 OD

the precision is 0. 01 OD

linearity is prior to 99. 7 %

RSD is less than 0. 69 %; the maximum counting rate of photons in the Cy3 fluorescence excitation test is greater than 107

and the counting error is less than 0. 02 %

which meet the practical requirements.