Constructing　heterojunction　is　an　important　method　to　improve　the　performance　of　photocatalyst　for　CO2　reduction.　In　this　work,　W18O49　nanosheets　(NSs)　were　grown　on　the　surface　of　SiC　nanocages　(NCs)　to　form　the　sea　urchin　ball　morphology　by　solvothermal　method.　The　SiC-W18O49　composite　photocatalyst　processes　1D　S-scheme　heterojunction　electron　transport　pathway.　The　special　urchin　morphology　provides　a　large　surface　area　for　the　contact　between　photocatalyst　and　CO2　reactants.　Meantime,　the　S-scheme　internal　electric　field　at　the　heterogeneous　interface　of　SiC-W18O49　composite　photocatalyst　can　effectively　promote　the　separation　and　migration　of　photogenerated　carrier　pairs　owing　to　1D　heterojunction　structure.　The　photocatalytic　CO2　reduction　products　(CO　+　CH4　+　CH3OH)　can　be　produced　up　to　21.87　μmol　g−1　h−1　by　SiC-W18O49　composite　photocatalyst,　which　was　3.38　and　3.71　times　of　the　total　reduction　activity　of　the　parent　SiC　and　W18O49,　respectively.　This　work　will　provide　a　new　idea　for　the　design　of　heterojunction　morphology　and　structure　for　boosting　photocatalytic　CO2　reduction.　©　2023　Dalian　Institute　of　Chemical　Physics,　the　Chinese　Academy　of　Sciences