A target catalyzed hairpin assembly combined with DNAzyme was adopted to establish a simple and sensitive method for visual detection of salmonella specific DNA fragment. Capture probe was designed by specific salmonella DNA segments. When target was present, capture probe opened and started the CHA reaction. H1-H2 diploid DNAzyme structure was formed and caused chromogenic reaction. The experiment was carried out to select optimal content of CP, H1, H2, and pH of buffer solution, and analyze the sensitivity and specificity. The results showed that the system had a good generality and met the requirements of the naked eye visual detection. The detect limit of this method was 3.9 pM and there was a linear correlation. Setting up of this method laid basis for visual detection of food-borne bacteria.