The molecular probes for PET-CT tumor detection are radionuclide molecular imaging probes, optical molecular imaging probes and magnetic resonance molecular imaging probes. 1. Radionuclide molecular imaging probes: It is the most applied class of probe markers. It mainly includes metabolic imaging probes, cell proliferation imaging probes, apoptosis imaging probes and so on. 2. Optical molecular imaging probes (1) Fluorescent dye-labeled probes: most fluorescent dyes have a certain degree of toxicity, which is not conducive to clinical application. (2) Quantum dot labeled probe: This probe has been successfully used for tumor angiogenesis imaging of subcutaneous graft tumors in mice. (3) Activatable probes: generally used for functional imaging of enzyme activation. (4) Raman probe. (5) Photoacoustic imaging probe: it can get high contrast and high resolution reconstruction image, and has the advantage of no side effect, which provides an important detection means for the non-destructive testing technology of biological tissues. 3. Magnetic resonance molecular imaging probe: initially applied to multi-modal imaging of tumor-bearing mice. Specific can go to the regular hospital to consult the doctor.