The (100) surface of SrTiO3 is inefficient for solar photocatalytic performance because its wide bandgap restricts the response to visible light. The effects of the different surface termination and the doped atoms are investigated to manipulate the solar photocatalytic behavior of the surface. The results reveal that the band edges for the Ti/O-terminated (100) surface of SrTiO3 (SS-I) can straddle the redox potentials for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), but this is not true for the Sr/O-terminated one (SS-II). However, we successfully make the band edges of SS-II meet the HER and OER conditions by the doped Te and Po atoms (Te-SS-II and Po-SS-II), after trying the doped elements of the IIIA-VIA group. The solar-to-hydrogen efficiency are 14.50 %, 9.89 %, and 12.75 % for SS-I, Te-SS-II, and Po-SS-II, respectively. The Gibbs free energies are calculated for each HER and OER. The result of -0.34 eV for the HER on SS-I indicates that this reaction can spontaneously proceed. Therefore, these surfaces are promisingly used for photocatalytic water splitting. The present findings provide helpful guidance to manipulate the photocatalytic water splitting on the (100) surfaces of SrTiO3 by choosing the terminal atoms or doped atoms on the surface.