Measurement of blood pressure has an effect on the results of oximetry. At present, the most commonly used clinical method of blood oxygen measurement is the optical method, measurement, the sensor needs to be set on the human finger, the near infrared light as an incoming light source, through the determination of the light conduction intensity of the tissue bed, to calculate the hemoglobin concentration and blood oxygen saturation. When measuring oxygen saturation, blood pressure was measured in the ipsilateral limb using a blood pressure meter, and the cuff airbag blocked blood flow and affected the oxygen saturation monitoring results. When measuring oxygen saturation, it should be done: 1. in a quiet state, the patient lies still on the bed, with hands on both sides of the body; 2. avoid monitoring oxygen saturation on the same limb when measuring blood pressure; 3. Prolonged continuous monitoring of oxygen saturation should be changed once every 2 hours; 4. Adjust the position of the fingers and finger cuffs so that the red light is directly in front of the nail bed, and the measuring finger is flush with the heart during monitoring; 5. Record the readings accurately when the data are stable; 6. Pay attention to some factors that may lead to inaccurate test results, such as displacement of the finger cuff, poor contact with the subject, bright light environment that may cause signal interference with the oximetry probe, too short a monitoring time, vasoactive drugs, nail polish, thick skin or skin pigmentation, and so on. Any abnormalities should be promptly notified to the doctor and appropriate treatment plan should be taken.