We perform an ab initio study on the electronic structure and charge density of the s-oxygen under high pressure, which is obtained by powder x-ray diffraction experiment recently. Our results show that the hybridization among the a σ*g.πu and π*g bands in the ε-oxyen are not significant even at megabar pressure.Pressure-induced metallization occurs due to the band overlapping near the Fermi level at about 50 GPa. A new network along the b-axis is formed and the O8 characteristic in the e phase disappears above 50 GPa even though the symmetry remains unchanged.