Improving　the　utilization　efficiency　of　heavy　rare　earth　is　currently　a　research　hotspot　in　the　field　of　rare　earth　permanent　magnets.　In　this　article,　the　effect　and　mechanism　of　pressure-assisted　grain　boundary　diffusion　(PGBD)　on　improving　Tb　utilization　efficiency　was　investigated.　The　magnetic　properties,　microstructure,　and　magnetic　domain　morphology　of　the　PGBD　magnets　were　compared　and　analyzed　in　relation　to　conventional　grain　boundary　diffusion　(CGBD)　magnets.　The　results　shows　that　the　PGBD　process　promoted　Tb　diffusion　into　the　magnets.　The　residual　layer　thickness　of　the　PGBD　magnets　was　thinner　than　that　of　the　CGBD　magnets,　demonstrating　that　the　PGBD　process　could　allow　more　Tb　to　diffuse　into　the　magnets.　The　formation　of　a　more　complete　and　deeper　core-shell　structure　in　the　PGBD　magnets　significantly　enhances　their　resistance　to　demagnetization　fields,　thereby　resulting　in　an　increased　coercivity.　The　PGBD　process　exhibits　a　reduction　in　TbH3　usage　by　approximately　0.2　wt%　compared　to　the　CGBD　process,　while　maintaining　an　equivalent　level　of　coercivity　increment.　These　findings　highlight　the　efficacy　of　the　PGBD　process　in　enhancing　Tb　utilization　efficiency　and　conserving　Tb　resources.　©　2023