The invention relates to the technical field of detection, and provides a method and system for measuring oxyhemoglobin saturation in blood. The method includes the steps that two parallel light emitting diodes are controlled to periodically emit red light and infrared light to a finger to be detected the red light and the infrared light which are projected through the finger are detected and converted into a red light electrical signal and an infrared light electrical signal pulse components in the two electrical signals are separated out to obtain separated red light variable quantity in one period and infrared light variable quantity in one period the oxyhemoglobin saturation in blood is calculated according to the red light variable quantity and the infrared light variable quantity the oxyhemoglobin saturation is amplified, filtered, and then converted into a digital signal by an analog-digital converter for display. According to the technical scheme, the method and system have the advantages of non-invasive detection and real-time detection.
