The invention discloses a flexible wearable sleep physiological parameter detection method and device. Conventional sleep respiration detection is not combined with heart rate and blood oxygen. The flexible wearable sleep physiological parameter detection device comprises a heart rate and blood oxygen detection module, a temperature and moisture detection module and assorted mobile phone terminal software, wherein the heart rate and blood oxygen detection module and the temperature and moisture detection module can support bluetooth 5.0; and the mobile phone terminal software is used for receiving the temperature, the moisture, the reflection infrared light data and the reflection infrared light data, detecting the respiration situation, performing filtering on the reflection infrared light data, performing peak seeking, performing calculation to obtain the heart rate value, performing FFT alternation on the reflection infrared light data and the reflection infrared light data, and obtaining the blood oxygen concentration value combined with a Beer-Lambert Model. The flexible wearable sleep physiological parameter detection method and device disclosed by the invention also support a manner that the data is stored, and the CSV formatted file is transmitted out for secondary research. The flexible wearable sleep physiological parameter detection device disclosed by the invention is integrated on a flexible circuit board, and is stuck to the skin below the nose, so that the wearing is convenient; and the flexible wearable sleep physiological parameter detection device has very low active RF and MCU electric current, is low in power dissipation, and is suitable for long-time monitoring.