The invention discloses a method for rapid detection of Salmonella typhimurium based on the photothermal effect of an immunomagnetic nanomaterial. According to the method, a standard curve for the values of temperature rises and the numbers of Salmonella typhimurium is established by using the photothermal effect of an immunomagnetic nanomaterial, and the value of the temperature rise of a samplecan be substituted into the standard curve so as to obtain the number of Salmonella typhimurium in the sample; and the three links consisting of enrichment and separation, detection and sample inactivation are effectively integrated by using the magnetic and photothermal effect of the immunomagnetic nanomaterial. The method provided by the invention is sensitive, safe, rapid, portable and cheap; experimental results verify that the method has a minimal detection limit of 300 bacteria and the temperature rise value delta T is linearly related to the Salmonella typhimurium number in a range of 300-1000; therefore, the method provided by the invention has good practical application prospects and can be applied to actual rapid detection of Salmonella typhimurium.