Abstract: The growth and reproduction of microorganisms in fracturing fiuid has always been the urgent problem in the development of shale reservoirs. And the key solution is to research and develop the antibacterial agent with the features of high efficiency, multiple function and low cost. Flavobacterium C was taken as the model strain and its growth curve was surveуed. Then, the antibacterial performance of a new fracturing fiuid additive of quaternary amine salt (i.e., cetyl trimethylammonium bromide (CTMAB)) in three fracturing fiuids (SF-A, F108 and linear gel) was studied in detail. It is indicated that CTMAB is effectively antibacterial for all fracturing fiuids adopted in the construction at the construction concentration. Furthermore, CTMAB is superior to formol antibacterial agent in term of antibacterial effect in linear gel if their concentration is the same. To sum up, CTMAB is a kind of good broad-spectrum antibacterial agent with the effect of surface activitу.