The invention specifically relates to a method for detecting 
Salmonella typhimurium, belonging to the field of 
analytical chemistry. The method comprises the following steps: modifying LumAuNPs with probe 
DNA so as to obtain a 
chemiluminescence probe; modifying a 
magnetic bead by using captured 
DNA with a hairpin structure so as to obtain a captured 
DNA-modified 
magnetic bead; modifying another 
magnetic bead by using 
aptamer DNA and 
aptamer complementary sequence DNA so as to obtain 
a DNA-modified magnetic beads; adding a 
Salmonella typhimurium solution containing a target into a solution of the DNA-modified magnetic bead, carrying out 
magnetic separation, sucking up obtained 
clear liquid, adding the 
clear liquid into a solution of the captured DNA-modified magnetic bead, and connecting the 
chemiluminescence probe with the surface of the magnetic bead via catalytic hairpin self-
assembly technology under the action of hybridization of the probe DNA on the 
chemiluminescence probe; and after 
magnetic separation and adding 
hydroxylamine-O-
sulfonic acid for generation of chemiluminiscence so as to realize determination of 
Salmonella typhimurium. According to the invention, LumAuNPs-
hydroxylamine-O-
sulfonic acid is used as a chemiluminescence 
system, so the intensity of a detection 
signal is improved; and mismatched bases are introduced into the probe DNA, so background signals are reduced, and determination sensitivity is improved. The method provided by the invention has the advantages of easiness and high sensitivity.