Debinding　heat　treatment　process　play　an　important　role　in　forming　quality　of　3D　printing　ceramics.　At　present,　the　alumina　green　body　prepared　by　light　curing　3D　printing　is　sintered　after　debinding　in　air.　The　final　alumina　ceramics　may　have　defects　such　as　micro　cracks,　resulting　in　poor　mechanical　properties.　Direct　heating　and　debinding　in　air　may　lead　to　cracks　caused　by　reaction　between　resin　and　oxygen　in　green　body.　To　avoid　this　situation,　this　work　studies　the　printing　heat　treatment　process　of　alumina　ceramics　based　on　digital　light　processing　(DLP)　technology.　The　alumina　ceramic　green　body　prepared　by　3D　printing　was　degreased　either　in　air　or　in　argon,　and　their　macro　morphologies　were　compared　with　each　other.　It　is　found　that　there　are　micro　cracks　in　the　alumina　green　body　debinding　in　air.　After　being　sintered　in　air,　the　alumina　ceramics　was　obtained　and　their　micro　morphology　and　macro　properties　were　characterized.　Average　grain　size　of　alumina　ceramics　debinding　in　argon　was　larger　than　that　directly　debinding　in　air,　while　the　grain　structure　was　dense　without　obvious　pore　and　impurity.　Moreover,　in　terms　of　mechanical　properties,　alumina　ceramics　debinding　in　air　have　higher　compressive　strength.　The　highest　density　of　alumina　debinding　in　argon　reaches　96.72%,　and　the　compressive　strength　reaches　761.7　MPa,　significantly　improved　as　compared　with　the　one　debinding　in　air.