A new kind of complex sensing membrane based on fluorescence quenching for oxygen detection has been prepared by using formamide and tetraethoxysilane as the main components, Ru(phy)(3)Cl-2 as the indicator. The sensing membrane is uniform and crack-free, and the indicators in it have low leaking rate. For the detection of oxygen based on fluorescence quenching, this sensing membrane has the specialities of high accuracy, fast response, good stability and reproducibility.