Abstract: Magnetic nanoenzyme color development technology is a new technology, which is used to rapid, sensitive, and visual detection of targets based on the peroxidase-like properties of magnetic nanoenzyme. Compared with natural enzymes, magnetic nanoenzyme has the advantages of easy preparation, preservation, recovery and low cost. In this paper, the catalytic mechanism and activity regulation of magnetic nanoenzyme are briefly introduced, the application of magnetic nanoenzyme chromogenic technology in the detection of pesticide and ceterinary drug residues, foodborne pathogens and other harmful substances in food are introduced emphatically. At present, the technology still has problems, such as weak enzyme activity, narrow detection range, and poor selectivity. Some suggestions are given for resolving above problems, and its future development direction is prospected.