Salmonella (Sal) and Escherichia coli (Esc) are two common foodborne pathogens that cause significant harm to humans. Therefore, strict control of Esc and Sal in food and the environment is essential. Herein, we developed a colorimetric/fluorescence dual-mode strategy for the detection of two pathogenic bacteria. Taking advantage of the characteristic that concanavalin A (ConA) can capture bacteria via the recognition of the sugar residues, it was coupled with magnetic nanoparticles (MNPs) to form MNPs@ConA as the capture probe. In addition, the antibody (Ab) can specifically recognize the bacteria, and after coupling with CdTe quantum dots (QDs), QDs@Ab was employed as the signal probe. This study shows that MNPs can catalyze 3,3 ',5,5 '-tetrame-thylbenzidine (TMB) to generate blue oxTMB to be recognized by the naked eye, while QDs exhibited strong fluorescence, which can also be observed by the naked eye, allowing for a clear differentiation in Sal and Esc detection. The signal was linearly correlated with the target bacteria with a satisfied visualized results. The practicability of the method was verified using milk tea, milk, and juice samples, with recovery rates ranging from 93.5 % to 106 %. The feasibility of this method for the detection of Sal and Esc was validated, and it poses a significant potential for food safety monitoring.