Twinned　crystals　of　Cu2-xEuxO　were　fabricated　through　a　gas-liquid　reaction　and　collaborative　thermal　annealing　method.　The　effective　doping　of　the　europium　(Eu)　atoms　in　twinned　crystal　Cu2O　is　attributed　to　the　mechanisms　of　ion　diffusion　and　capture　doping.　To　better　investigate　the　room-temperature　ferromagnetism　(RTFM)　of　twinned　crystal　materials,　further　analysis　was　performed　on　the　ferromagnetic　properties　of　Cu2-xEuxO　bulk　using　field-cooling　and　zero-field-cooling　measurements.　The　magnetic　properties　of　the　twinned　crystal　Cu2O　mainly　arise　from　the　electronic　spin　polarization　on　the　(111)　twinned　crystal　plane.　Furthermore,　the　parabolic　characteristics　of　its　saturation　magnetization　can　be　explained　by　two　competing　mechanisms　present　in　the　doping　process.　To　investigate　the　magnetic　origin　of　the　twinned　crystal　Cu2-xEuxO　bulks,　the　spatial　distribution　of　spintronic　state　density　was　analyzed　using　four　distinct　structural　models.　The　results　indicate　that　Eu　atoms　mainly　contribute　to　the　magnetism　of　the　Cu2-xEuxO　bulks.　The　linkage　between　4f　electron-associated　spin-polarized　states　and　carriers　in　the　twinned　crystal　Cu2-xEuxO　bulks　makes　them　promising　for　spintronics　applications.　©　2024　American　Chemical　Society.