High　active　Pd-based　catalyst　with　low　loading　capacity　for　CO　oxidative　coupling　with　methyl　nitrite　(MN)　to　dimethyl　oxalate　(DMO)　has　aroused　great　interest　in　the　large-scale　production　of　DMO　for　the　next　hydrogenation　to　bring　forth　ethylene　glycol　(EG).　Here,　spinel　composite　oxide　support,　namely　MgAl2O4,　had　been　prepared　through　three　different　methods:　solid　combustion　method　(MAO-SC),　hydrothermal　method　(MAO-HT)　and　co-precipitation　method　(MAO-CP),　and　further　Pd　nanoparticles　were　anchored　to　the　surface　of　MgAl2O4　through　a　simple　wetness　impregnation　method.　In　the　CO　direct　esterification　to　DMO　reaction,　the　Pd/MAO-SC　catalyst,　which　used　MgAl2O4　support　prepared　by　solid　combustion　method,　exhibited　the　highest　intrinsic　activity　with　Turnover　frequency　(TOF)　value　of　2.39　s(-1)　and　DMO　weight　space-time　yield　(956.8　g.kg(cat)(-1).h(-1))　with　44.1　%　CO　conversion　and　97.8　%　DMO　selectivity,　and　showed　negligible　attenuation　of　activity　during　the　process　of　continuous　reaction　for　100　h.　The　characterization　results　confirmed　that　abundant　oxygen　defect　sites　occurred　in　MAO-SC　synthesized　by　combustion　method　not　only　can　help　to　anchor　the　Pd　nanoparticles　with　appropriate　size　and　dispersion,　but　also　can　promote　the　interfacial　electron　transfer　from　MgAl2O4　support　to　Pd　nanoparticles,　thus　significantly　enhancing　the　metal-support　interaction　(MSI)　and　providing　more　CO　bridge-adsorption　sites　that　is　favorable　for　the　CO　oxidative　coupling　with　MN　to　DMO　reaction.