Recently, stretchable and wearable health monitoring equipment has greatly improved human’s daily life, which sets higher demands for portable power source in stretchability, sustainability, and biocompatibility. In this work, we proposed a stretchable triboelectric nanogenerator (TENG) based on stretchable poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/porous carbon hybrid for oxyhemoglobin saturation (SpO2) monitoring. To combine advantages of carbon material for its high conductivity and organic electrode for its high stretchability, we spin-coated a solution of PEDOT:PSS/porous carbon onto a plasma-treated pre-stretched Ecoflex film to fabricate a stretchable electrode with rough surface. Due to its roughness and high potential difference with the dielectric material, the stretchable-electrode-based TENG exhibited better performance compared to the pristine TENG based on carbon or PEDOT:PSS material. The output voltage and current reached up to 51.5 V and 13.2 μA as the carbon concentration increased. More importantly, the performance further increased under large strain (100%) which is suitable for wearable systems. Finally, the device demonstrated its application potential for powering a flexible blood oxygen monitor. This simple and cost-effective method can enhance the stretchability and stability of organic/inorganic electrode-based TENG, which paves the development of high-performance stretchable TENG.