3D　printing　technology　can　rapidly　transform　digital　model　into　physical　realization,　and　has　been　widely　studied　in　many　fields.　However,　its　developments　are　very　slow　in　the　fields　of　catalysis　and　reaction　engineering,　due　to　harsh　application　environments.　Here,　we　report　that　metal　3D　printing　is　used　to　prepare　Nickel-based　Self-Catalytic　Reactor　(Ni-SCR)　for　COx　methanation.　The　optimized　Ni-SCR　samples　exhibit　unique　surface　properties.　The　catalytic　results　reveal　that　they　also　possess　premium　methanation　performance.　This　work　will　facilitate　the　developments　both　in　3D　printing　technologies　and　novel　catalytic　systems.