Cold laser can treat olfactory loss caused by obstruction and ventilation obstruction, and is not effective for olfactory loss caused by other reasons such as olfactory nerve injury. Cold laser treatment uses the photochemical and thermal effects of laser, which can quickly cut the local lesion tissues, rapidly coagulate and stop bleeding, expand the area of nasal cavity ventilation and improve ventilation. If hypertrophic rhinitis, acute and chronic rhinitis, sinusitis, etc. lead to congestion and swelling of nasal mucosa, the airflow can not enter the olfactory area normally, resulting in olfactory malfunction, under the premise of ineffective conservative treatment, cold laser treatment can be carried out in accordance with the doctor’s prescription. For olfactory nerve damage caused by viral infection, olfactory nerve damage caused by trauma or olfactory bulb damage caused by intracranial olfactory bulb, cold laser treatment is not effective. In case of olfactory dysfunction, it is recommended that the patient should consult a doctor in time to find out the cause of the disease and carry out standardized treatment under the doctor’s guidance.