Mycotoxins can enter and accumulate in the human body through contaminated foods, which is extremely harmful to human health. A rapid, sensitive, accurate and effective method is needed to detect mycotoxin contamination. With the advancement of science and technology, various types of biosensors have been continuously developed. Among them, magnetic and fluorescent sensors can produce sensitive and fast optical responses to the target compounds. This dual-function sensor has been widely used in the field of biological detection. This article reviews the application and future prospects of biosensors combining Fe₃O₄ magnetic nanoparticles with organic fluorescent materials, quantum dots, upconversion nanoparticles, metal nanoclusters or fluorescent carbon nanomaterials in the detection of mycotoxins. This review is expected to provide a reference for further research and application of Fe₃O₄ magnetic and fluorescent sensors.