To explore the efficacy of olfactory training on olfactory and other non-motor symptoms in PD.

Inclusion Criteria:

1. PD was diagnosed according to the criteria of Movement Disorders and Parkinson Disease Group of Chinese Society of Neurology of Chinese Medical Association.
2. Olfactory score was 1 standard deviation lower than the corresponding age norm;
3. no medication plan in the past four weeks or no change in medication plan in the past four weeks, which can be maintained until the end of the experiment; 4.40-75 years old, with normal vision, hearing and language understanding and expression ability;

5.Good cooperation of patients

Exclusion Criteria:

1. Parkinson's syndrome and Parkinson's plus syndrome caused by cerebrovascular disease, encephalitis, trauma, drugs, etc.;
2. Neuropsychiatric diseases that may affect the sense of smell, such as depression, anxiety, schizophrenia, etc.;
3. History of nasal disease or surgery, such as rhinitis, sinusitis, nasal septum deviation, etc. Upper respiratory tract infection in the past 3 weeks;
4. Long-term smoking and occupations that inhale chemical irritants for a long time.