Expecting an early and accurate diagnosis of Parkinson’s disease has always been a challenge for neurologists. The traditional method of diagnosis, which is mainly based on history, signs and other clinical manifestations, often makes it difficult to accurately identify Parkinson’s disease and similar diseases at an early stage. A series of studies conducted by scholars in the United Kingdom and Canada to compare clinical diagnosis with pathological diagnosis found that even physicians specializing in Parkinson’s disease and other movement disorders may have a 20%-25% diagnostic bias in the diagnosis of Parkinson’s disease. These diagnostic biases exist mainly in the identification of Parkinson’s disease with Parkinson’s superimposed syndrome and tremor-like disorders. In order to improve the diagnostic accuracy of Parkinson’s disease, basic and clinical medical scientists engaged in neurology, nuclear medicine, and imaging have continued to explore 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 the nigrostriatal dopaminergic neurons in the midbrain, which leads to a deficit in the nigrostriatal dopaminergic transmitter system. Although the gold standard for diagnosis is neuropathologic diagnosis based on obtaining nigrostriatal tissue, it is currently not 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 of using imaging methods to show specific molecules at the tissue level, cellular and subcellular levels, reflecting changes at the molecular level in vivo, and to qualitatively and quantitatively study their biological behavior in imaging. Molecular imaging is an emerging discipline that combines molecular biology techniques with modern medical imaging, and opens up a whole new world for the diagnosis and treatment of diseases through the development of new tools, reagents, and methods to detect cellular and molecular abnormalities in the course of a disease.The combination of PET technology and new tracers is one of the main techniques of molecular imaging. Within the human nigrostriatal dopaminergic transmitter system there are a series of characteristic metabolic enzymes, transporter proteins, and receptors, etc., which are involved in the processes of dopamine synthesis, storage, release, reuptake, and production of biological effects. In patients with Parkinson’s disease, these metabolic enzymes, transporter proteins and receptors, etc. of the nigrostriatal dopaminergic transmitter system undergo characteristic changes, which are significantly different from those in Parkinson’s superimposed syndrome and tremor-like disorders. Scientists from radiomedicine, chemistry, and other disciplines have synthesized radiotracers that specifically bind to these metabolic enzymes, proteins, receptors, and so on. When these tracers are injected into the body of the tested person, they can be highly specific to bind to specific proteins and other molecules in the substantia nigra striata system. Radionuclides are bound to these tracers, which can be measured and imaged by a PET instrument, thus showing the changes in the distribution and quantity of metabolites in the body that are bound to these tracers. PET imaging currently used in the diagnostic field of Parkinson’s disease includes: 1, dopaminergic system imaging: dopamine transmitter imaging, dopamine transporter (DAT) imaging, type II vesicular monoamine transporter (VMATII) imaging and dopamine D2 receptor imaging; 2, non-dopaminergic system imaging: glucose metabolism imaging, 5-hydroxytryptophan system imaging, microglial cell imaging, interstitial iodine (MIBG) and interstitial iodine (MIBG). phenylmethylguanidine (MIBG) imaging and so on. 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 at present. Despite multiple limitations, vesicular monoamine transporter type II (VMATII) imaging is considered to be the most reliable tracer to respond to the density of synaptic endings in dopaminergic neurons. In China, the Department of Nuclear Medicine of the First Affiliated Hospital of the General Hospital of the People’s Liberation Army (PLA) and the Department of Nuclear Medicine of Shanghai Huashan Hospital have made great progress in the early diagnosis of Parkinson’s disease by applying dopamine transporter imaging. The application of PET and other molecular imaging techniques combined with specific radionuclide tracers can show the characteristic metabolic changes of Parkinson’s disease in vivo, making it possible to objectively detect and evaluate the pathophysiological changes of Parkinson’s disease patients. The application of this technology in the field of Parkinson’s disease can not only accurately diagnose Parkinson’s disease at an early stage when the clinical manifestations are atypical, but also help in staging Parkinson’s disease and objectively evaluating the efficacy of drugs, which undoubtedly provides an effective and reliable objective index for the diagnosis and treatment of Parkinson’s disease and makes the diagnosis and treatment of Parkinson’s disease advance to a new level. The application of this technology will benefit Parkinson’s disease patients.