Alumina　ceramics　used　in　microwave　systems　are　susceptible　to　the　multiplication　of　secondary　electron　emission　on　the　surface　due　to　the　influence　of　resonance　between　electrons　and　the　radiofrequency　electric　field,　and　a　detrimental　multipactor　effect　may　therefore　be　triggered.　For　the　alumina-loaded　microwave　components,　it　is　essential　to　achieve　low　secondary　electron　yield　(SEY)　on　the　inserted　alumina　surfaces　to　mitigate　multipactor.　In　this　work,　to　achieve　an　ultralow　SEY　surface　of　alumina,　two　recognized　low-SEY　treatments　were　combined.　For　the　primary　SEY　suppression,　a　series　of　microstructures　were　fabricated　on　the　alumina　surfaces　with　varied　porosity　and　aspect　ratio　at　the　hundred-micrometer　scale　by　infrared　laser　etching.　The　microstructure　with　52.14%　porosity　and　1.78　aspect　ratio　showed　an　excellent　low-SEY　property,　which　could　suppress　the　SEY　peak　value　(　delta　(m)　)　of　alumina　from　2.46　to　1.00.　For　the　secondary　SEY　suppression,　the　SEY　dependence　of　TiN　coating　on　sputtering　parameters　was　studied,　and　the　lowest　delta　(m)　of　1.19　was　achieved　when　the　gas　flow　ratio　of　Ar:N-2　was　15:7.5.　Thereafter,　by　depositing　TiN　ceramic　coating　onto　the　laser-etched　porous　samples,　an　ultralow　SEY,　with　delta　(m)　of　0.69,　was　achieved　on　the　alumina　surfaces.　The　simulation　work　revealed　the　impact　of　dielectric　surface　charge　on　electron　multiplication　and　revealed　a　mechanism　of　using　low-SEY　surfaces　to　inhibit　multipactor.　Some　coaxial　filters　filled　with　alumina　were　fabricated　for　verification;　the　results　revealed　that　the　multipactor　threshold　increased　from　125　W　to　425　W　after　applying　the　TiN-coated　porous　alumina,　and　to　650　W　after　treating　another　multipactor-sensitive　area　with　the　same　low-SEY　process.　This　work　developed　an　advisable　method　to　sharply　reduce　SEY,　which　is　of　great　significance　for　the　multipactor　mitigation　of　alumina-loaded　microwave　components.