Fabricate surface-enhanced Raman scattering (SERS) substrate with low cost and high performance through simple method is a challenge and worthy of work. Herein, an excellent Cu2O SERS substrate with porous octahedron structure was synthesized by brief calcining Cu-MOFs in Ar, air and H-2/Ar gas environment at 350 degrees C successively. The as-obtained octahedral Cu2O was utilized as SERS substrate to measure dye molecules and organic pollutants, which exhibited splendid sensitivity for the detection of methylene blue and 4-mercaptopyridine (4-MPY) with the ultralow limit of 5 x 10(-9) M and 5 x 10(-10) M, respectively. The maximum relative standard deviation for detection of 4-MPY is as low as 12.3%, which is less than limiting step in quantitative SERS (15.0%). The above excellent results are due to outstanding synergistic effect of electromagnetic enhancement of oxygen vacancy on the Cu2O surface and chemical enhancement of the Cu-S bonds formation. The fabricated Cu2O possesses superior sensitivity, selectivity and reproducibility for SERS detection of probe molecules with sulfhydryl groups and may be a prospect candidate in the practical application.