Expecting an early and accurate diagnosis of Parkinson’s disease has always been a challenge for neurologists. Traditional methods of diagnosis based primarily on clinical manifestations such as history and signs often have difficulty in accurately identifying Parkinson’s disease and a number of similar disorders at an early stage. A series of studies conducted by scholars in the United Kingdom and Canada comparing clinical diagnosis with pathological diagnosis found that even physicians specializing in the study of movement disorders such as Parkinson’s disease may have a diagnostic bias of 20%-25% when diagnosing Parkinson’s disease. These diagnostic biases exist mainly in the differentiation of Parkinson’s disease from Parkinson’s superimposed syndrome and tremor-like disorders. In order to improve the diagnostic accuracy of Parkinson’s disease, basic and clinical medical doctors engaged in neurology, nuclear medicine and imaging have continuously explored the application of novel molecular imaging techniques for the diagnosis of Parkinson’s disease, and have made significant progress. The core pathological change in Parkinson’s disease is a degenerative lesion of nigrostriatal dopaminergic neurons in the midbrain, resulting in a deficiency of the nigrostriatal dopaminergic transmitter system. Although the gold standard for diagnosis is a neuropathological diagnosis based on obtaining nigrostriatal tissue, it is not yet possible to obtain midbrain tissue under somatic conditions. We can show the absence of the nigrostriatal dopaminergic transmitter system in vivo with the help of molecular imaging methods. Molecular imaging is the science that uses imaging to show specific molecules at the tissue level, cellular and subcellular levels, reflecting changes at the molecular level in the living state, and to study qualitatively and quantitatively their biological behavior in terms of imaging. Molecular imaging is an emerging discipline that combines molecular biology techniques with modern medical imaging, opening up a whole new world of diagnostic and therapeutic possibilities by developing new tools, reagents and methods to detect cellular and molecular level abnormalities in disease processes. Within the human nigrostriatal dopaminergic transmitter system there are a series of characteristic metabolic enzymes, transporter proteins and receptors involved in the synthesis, storage, release, reuptake and production of biological effects of dopamine. In Parkinson’s disease, these metabolic enzymes, transporter proteins and receptors of the nigrostriatal dopaminergic transmitter system undergo characteristic changes, which are significantly different from Parkinson’s superposition syndrome and tremor-like diseases. Scientists in radiology, chemistry and other disciplines have synthesized radioactive tracers that bind specifically to these metabolic enzymes, proteins, receptors, etc. When these tracers are injected into the subject, they can bind highly specifically to specific proteins and other molecules within the nigrostriatal system. These tracers are bound with radionuclides, which are measured and imaged by a PET instrument, thus showing changes in the distribution, quantity, and other indicators of metabolites in the body to which these tracers are bound. PET imaging in the field of Parkinson’s disease diagnosis includes: 1) imaging of dopaminergic system: dopamine transmitter imaging, dopamine transporter (DAT) imaging, vesicular monoamine transporter type II (VMAT II) imaging and dopamine D2 receptor imaging; 2) imaging of non-dopaminergic system: glucose metabolism imaging, 5-hydroxytryptaminergic system imaging, microglia imaging, myocardial inter-iodobenzylguanidine (MIBG) imaging, etc. (MIBG) imaging, etc. Among them, dopamine transporter imaging can be used to evaluate the functional status of striatal presynaptic dopaminergic nerve fiber endings and is considered to be the most sensitive molecular imaging marker for PD. Despite various limitations, vesicular monoamine transporter type II (VMAT II) imaging is considered to be the most reliable tracer of dopaminergic neuronal synaptic terminal density. In China, the Department of Nuclear Medicine of the First Affiliated Hospital of the PLA General Hospital and the Department of Nuclear Medicine of Shanghai Huashan Hospital have made great progress in applying dopamine transporter imaging for early diagnosis of Parkinson’s disease. The application of molecular imaging techniques such as PET combined with specific radionuclide tracers can show the characteristic metabolic changes of Parkinson’s disease in the in vivo state, making it possible to objectively detect and evaluate the pathophysiological changes in patients with Parkinson’s disease. The application of this technology in the field of Parkinson’s disease not only allows accurate diagnosis of Parkinson’s disease at an early stage when clinical manifestations are atypical, but also helps to stage the disease and objectively evaluate the efficacy of drugs in Parkinson’s disease, which undoubtedly provides effective and reliable objective indicators for the diagnosis and treatment of Parkinson’s disease and advances the diagnosis and treatment of Parkinson’s disease to a new level. The application of this technology will benefit patients with Parkinson’s disease.