Nanozymes, nanomaterials with similar catalytic activity and enzymatic reaction characteristics to natural enzymes, can overcome natural enzymes’ disadvantages of high cost and poor stability, but they are faced with the problem of low catalytic activity, which to some extent restricts the rapid development of the interdisciplinary field of nanobiology. With the development of spherical aberration correction electron microscopy, different kinds of single-atom nanozymes (SAzymes) have been developed and rapidly become the research frontier in the field of nanozymes. SAzymes have uniformly dispersed active sites and precisely designed coordination structures, which imparts them with higher catalytic activity. This is particularly important for the development of sensitive, efficient and rapid food detection technologies. This article mainly reviews the development history of SAzymes, analyzes the latest research trends in the activity of SAzymes, and introduces in detail the recent progress in the application of SAzymes to rapid food detection. Finally, the challenges and future research directions of SAzymes are discussed.