There is currently no test that can directly clarify the diagnosis of Parkinson’s disease. Positron emission tomography (PET) can help confirm the diagnosis of early stage Parkinson’s disease, but this test is expensive and cannot be used as a routine test. Brain CT examination and brain MRI examination have no characteristic changes in either the early stage or late stage of Parkinson’s disease, and cannot provide direct value for the diagnosis, but can provide negative evidence, which can be used as differential diagnosis or negative evidence of Parkinson’s disease. It is meaningful for the diagnosis of secondary Parkinson’s signs. In general, confirming the diagnosis of Parkinson’s disease relies on a detailed history, clinical signs and symptoms, i.e., physician’s questioning, observation and examination. Symptoms can appear and develop very slowly, often starting in one upper extremity, gradually spreading to the ipsilateral lower extremity, and then to the contralateral upper and lower extremity. Some tremors or movement disorders are not even noticed until several years later. The main symptoms and signs are: 1. Resting tremor: It is often the first symptom, mostly starts in the distal part of one upper limb, appears or is obvious in the resting position, decreases or stops during casual movement, increases when nervous, and disappears after sleep. 2. Myotonicity: Increased resistance during passive movement of joints. It is characterized by consistent resistance during passive movement of joints, and the amount of resistance is basically not affected by the speed and force of passive movement, and may appear as “leadpipe-like ankylosis” or “gear-like ankylosis”. The ankylosis of the limbs, trunk and neck muscles can cause the patient to have a special flexion posture, which is characterized by forward head tilt, prone trunk flexion, elbow flexion of the upper limbs, wrist extension, forearm inversion, and slight bending of the hip and knee joints of the lower limbs. 3.Motor retardation: reduced casual movements, slow and clumsy movements. In the early stage, the movement is slow for fine movements such as unbuttoning and tying shoelaces, and then gradually develops into generalized slow movements. In the late stage, the combination of hypertonia makes it difficult to get up and turn over. The face is dull, the eyes are staring, and the transient eyes are reduced; the mouth, pharynx and palate muscles are impaired, the speech speed becomes slower, and the voice is low-pitched; when writing, it may show “writing hypermetropia”. 4, posture and gait disorders: balance function is reduced, easy to fall. In the early stage of the disease, the lower limb of the affected side drags when walking, and the upper limb swinging amplitude is reduced or disappeared, although the development of the disease, the pace gradually becomes smaller and slower, and the gait disorder is obvious when starting to turn. Sometimes the whole body stiffens during walking and cannot move. Sometimes step after step with small fragmented steps faster and faster, can not stop in time. 5. Other autonomic symptoms: greasy face, constipation, abnormal sweating, excessive salivation and drooling. Nearly half of the patients have depression or sleep disorder. Dementia occurs in about 15-30% of patients in the late stages of the disease. It is worth noting that Parkinson’s disease should be differentiated from some of the following diseases, such as idiopathic tremor, dystonic disorders, Parkinson’s syndrome (symptomatic) such as post-encephalitis, drug-induced, toxic, vascular-derived Parkinson’s syndrome, and multi-system atrophy, including olivopontocerebellar atrophy, standing hypotension syndrome, progressive supranuclear palsy, diffuse Lewy body dementia, etc. The above-mentioned diseases are poorly treated or ineffective with anti-Parkinsonian drugs.