Additive　manufacturing　(3D　printing)　technologies,　especially　vat　photopolymerization　(VPP),　provide　a　cost-effective　and　efficient　approach　for　the　fabrication　of　heat　dissipation　devices　with　complex　geometric　designs.　The　incorporation　of　inorganic　thermal　conductive　fillers　into　resin　matrix　is　widely　recognized　as　an　effective　way　to　enhance　thermal　conductivity.　Notably,　the　synergistic　effect　of　hybrid　fillers　can　further　enhance　thermal　conductivity.　However,　the　consequent　drastic　increase　in　viscosity　of　the　UV-curable　resin　may　decrease　the　success　rate　and　accuracy　of　printing　on　commercial　VPP　3D　printers.　In　this　work,　hexagonal　boron　nitride　(h-BN)　platelets　and　spherical　h-BN　together　with　β-Si3N4　are　introduced　into　the　UV-curable　resin　system.　Corresponding　results　proved　that　h-BN　together　with　β-Si3N4　provide　a　synergistic　effect　on　the　thermal　conductivity　enhancement　compared　to　the　filler　in　single　morphology　only.　Moreover,　owing　to　the　spherical　structure,　low-viscosity　UV-curable　resin　with　high　solid　content　can　be　prepared.　In　specific,　a　thermal　conductive　polymer　composite　material　with　a　solid　content　of　60　wt%　is　prepared,　which　exhibits　high　thermal　conductivity　(1.42　W/mK),　representing　an　enhancement　of　up　to　610　%　compared　to　neat　resin.　In　subsequent　application　demonstrations,　3D　printed　heat　dissipation　devices　with　as-prepared　resin　composite　material　have　been　shown　to　effectively　enhance　the　heat　dissipation　rate　for　the　heating　device.　©　2024　Elsevier　Ltd　and　Techna　Group　S.r.l.