Magnetic actuation technology (MAT) provides novel diagnostic tools for the early screening and treatment of digestive cancers, which have high morbidity and mortality rates worldwide. The application of magnetic actuation systems and magnetic robots in gastrointestinal (GI) diagnosis and treatment to provide a comprehensive reference manual for scholars in the field of MAT research are reviewed. It describes the basic principles of magnetic actuation and magnetic field safety, introduces the design, manufacturing, control, and performance parameters of magnetic actuation systems, as well as the applicability and limitations of each system for different parts of the GI tract. It analyzes the characteristics and advantages of different types and functions of magnetic robots, summarizes the challenges faced by MAT in clinical applications, and provides an outlook on the future prospects of the field.