Salmonella is among the four leading culprits of diarrhoeal afflictions and poses a considerable risk to human health. Based on the various action modes and colour rendering principles of cresol red (CR) and hydroxynaphthol blue (HNB)， a colorimetric detection of Salmonella in food by doul-dye SRCA has been created. The first step involved designing the SRCA primers for the invA gene of Salmonella， followed by optimization of the double-dye addition to establish a doul-dye SRCA colorimetric method. The method underwent evaluation via specificity， sensitivity， and detection limit tests， and its practical application performance was assessed by detecting 60 actual samples. The study identified that the ideal concentration ratio of HNB/CR was 0.6， which equated to 75 μmol/L HNB and 125 μmol/L CR. The test yielded positive results for 8 Salmonella strains and negative results for other strains. The sensitivity of the method was 6.8 CFU/mL， which was 100 times higher than that of PCR (6.8×102 CFU/mL)， and the detection limit was 9.5 CFU/mL， which was 100 times lower than that of PCR (9.5×102 CFU/mL). Importantly， the sensitivity， specificity， accuracy of this method were 100%， 98.2%， and 98.3%. Therefore， the doul-dye SRCA colorimetric method can detect Salmonella quickly， specifically and accurately. On the one hand， the combination of two dyes produces a higher hue contrast and a wider range of color variation between negative (purple) and positive (green) samples than using a single dye. On the other hand， the colorimetric dyes can be pre-added to the reaction system， which can effectively avoid secondary pollution.