In order to evaluate the flavouring uniformity in tobacco processing, we designed a quick online real-time measuring method to detect the volatile ethanol concentration of soluble flavour. The equipment consists of the sensor circuit, data acquisition unit and the data processing program. The sensor circuit includes a reference and a measure electrode, one measures the alcohol concentration of the tested position and the other measures the alcohol concentration of the environment background, thus the noise of the environment background can be eliminated. In the data acquisition unit, a high-precision specialized data acquisition module, Advantech's ADAM-4019, is used. It can convert RS-232 signals into RS-485 signals, and the communication between signal and computer are well established. The LabVIEW data processing program has statistics and analytical functions for recorded data. So, this kind of novel equipment can get the real-time voltage signals of alcohol sensor and convert them to the alcohol concentrations value, in digital and wave form.