Fluorine magnetic resonance imaging (19F MRI) is a promising imaging technique for cancer diagnosis because of its excellent soft tissue resolution and deep tissue penetration, as well as the inherent high natural abundance, almost no endogenous interference, quantitative analysis, and wide chemical shift range of the 19F nucleus. In recent years, scientists have synthesized various 19F MRI contrast agents. By further integrating a wide variety of nanomaterials and cutting-edge construction strategies, magnetically equivalent 19F atoms are super-loaded and maintain satisfactory relaxation efficiency to obtain high-intensity 19F MRI signals. In this review, the nuclear magnetic resonance principle underlying 19F MRI is first described. Then, the construction and performance of various fluorinated contrast agents are summarized. Finally, challenges and future prospects regarding the clinical translation of 19F MRI nanoprobes are considered. This review will provide strategic guidance and panoramic expectations for designing new cancer theranostic regimens and realizing their clinical translation.