Abstract: Continuous culture system of rumen mixed microorganisms is an instrument designed to in vitro simulate fermentation process of microbes in the rumen, in which medium is continuously added at a constant rate, and culture fluid is removed at the same rate. The instrument, consisting of different functional devices, can be used for researching nutrient metabolism of rumen microorganisms and evaluating nutritional value of rations. Until now, this kind of system can monitor the fermentation parameter and accurately measure the fermentation product like gas production, but it doesn’t equate to rumen environment. Based on comparison of advantages and disadvantages of structure designs and functional devices among several continuous culture systems in the literatures, some reasonable suggests were suggested for the instrumental design of continuous cultures for rumen microbes. In a word, the design of the continuous dynamic culture system is developed to the direction of automation, however, some aspects like the way of collecting chyme are needed to improve.