The precautions to be taken when inhaling oxygen include the adjustment of oxygen flow rate, regular observation, use and shutdown of oxygen, etc. 1. Adjustment of oxygen flow rate: When inhaling oxygen, attention should be paid to the adjustment of oxygen flow rate, which needs to be adjusted according to the specific conditions of the patient, such as patients with chronic obstructive pulmonary disease, it is recommended that the oxygen flow rate be 1-2L/min. 2. Regular observation: Observe whether the patient’s hypoxic condition improves; regularly check whether the catheter is smooth to prevent nasal blockage; regularly check the oxygen flow rate to ensure the correct amount of oxygen; regularly add distilled water in the humidified bottle. 3. Oxygen use and shutdown: Oxygen flow should be adjusted before putting on the oxygen tubing when inhaling oxygen; when stopping the use of oxygen, the oxygen tubing should be pulled out first, then the oxygen flow should be turned off, and finally the oxygen switch should be turned off. Oxygen intake must be carried out under the guidance of the doctor, who will choose the appropriate way of oxygen intake and flow rate according to the patient’s specific situation, to avoid blind oxygen intake.