Ultra-high-resolution fluorescent molecular tomography method refers to the use of fluorescent probe as a contrast agent to measure the light intensity at the tissue boundary and combine the model of photon propagation in the tissue to reconstruct the distribution image of the fluorescence optical properties and the optical parameters of the tissue. This imaging modality has the advantages of high sensitivity, high specificity, no trauma, and no radioactivity, and can be used to detect and diagnose various diseases, such as tumors, cardiovascular diseases, neurological diseases, etc. Case study of ultra-high-resolution fluorescence molecular tomography methods: Early diagnosis and therapeutic assessment of tumors: Using specific fluorescent probes, such as antibodies or ligands targeting tumor receptor or enzymes, tumor location, size, morphology and biomarkers can be quantitatively detected in vivo, so as to achieve early detection and molecular typing of tumors. At the same time, by monitoring the clearance speed and kinetic changes of fluorescent probes in tumor tissue, the therapeutic effect of drug or radiation therapy can be evaluated; Cardiovascular function and metabolic monitoring: By using fluorescent probes to label the blood flow or oxygen content in the heart or blood vessels, the function and metabolic status of the heart or blood vessels can be quantitatively measured in vivo, so as to monitor the health and disease of the cardiovascular system; Neuronal activity and synaptic plasticity mapping: By using fluorescent probes to label calcium ions or neurotransmitters within neurons or synapses, their activity and plasticity changes can be quantitatively measured in vivo, thus revealing the function and mechanism of the nervous system.