Abstract: This article studied the best inhibitory concentration of Fumaric acid sodium and Ploy-lysine, defined the best mixed ratio of their complex ratio of 10∶1.4 by taking E.coli as indicator bacteria while making inhibition zone diameter as an indicator, and then named the complex type of biological preservatives of DSG01.DSG01 had an obvious effect of water-holding capacity on fresh fish and a broad antibacterial spectrum, it had a good inhibitory on G-and G+bacteria and also worked on heat resistance Bacillus subtilis and psychrophilic bacteria (such as Pseudomonas fluorescens) .The results of this study provide the necessary experimental basis for DSG01 using in fresh fish preservation.