Nonlinear　optical　(NLO)　materials　have　received　unprecedented　attention　owing　to　their　capability　of　frequency　conversion　in　the　photoelectric　fields.　Yet,　how　to　acquire　a　crystal　with　a　noncentrosymmetric　(NCS)　structure　is　still　a　grand　challenge　for　the　NLO　material.　Herein,　a　new　quaternary　NCS　oxychalcogenide,　SrGeOSe2,　was　successfully　designed　and　synthesized　using　the　known　centrosymmetric　SrGeO3　as　a　maternal　structure　through　a　generic　partial　isovalent　anion　substitution　(PIAS)　strategy.　SrGeOSe2　belongs　to　the　NCS　space　group　P2(1)2(1)2(1)　(no.19)　and　features　a　one-dimensional　(1D)　chain　made　by　heteroligand　[GeO2Se2]　asymmetric　building　units.　Such　a　new　compound　exhibits　desirable　comprehensive　performance,　which　suggests　a　promising　IR-NLO　material:　type-I　phase-matching　feature,　strong　powder　second-harmonic　generation　intensity　(d(ij)　=　1.3　x　commercial　AgGaS2),　and　giant　powder　laser-induced　damage　threshold　(36　x　commercial　AgGaS2).　Furthermore,　the　systematic　theoretical　investigations　have　been　performed　for　the　deep　understanding　of　the　correlation　between　the　NCS　structure　and　the　NLO　property.　More　importantly,　this　work　pioneers　a　new　molecular　engineering　strategy　for　NCS　compounds　that　could　be　extended　to　other　NLO　materials.