The　mechanical　properties　of　Al[sbnd]Cu　alloys　produced　through　wire　arc　additive　manufacturing　(WAAM)　often　suffer　from　degradation　due　to　continuous　coarse　precipitate　phases　and　uneven　microstructure.　This　research　investigated　the　incorporation　of　h-BN　particles　into　the　deposition　process　of　Al[sbnd]Cu　alloys　during　WAAM,　examining　how　these　h-BN　particles　influence　the　microstructure　and　overall　properties　of　the　material.　The　results　indicate　that　h-BN　particles　promoted　grain　refinement,　leading　to　a　uniform　equiaxed　grain　microstructure　and　addressing　the　issue　of　uneven　interlayer　microstructure.　By　generating　a　large　number　of　fine,　dot-like　precipitates,　the　continuous　coarse　precipitates　distributed　along　the　grain　boundaries　(GBs)　were　disrupted.　The　tensile　strength　increased　from　171.8　±　18.7　MPa　to　254.4　±　8.7　MPa　in　the　horizontal　direction　and　from　183.6　±　19.4　MPa　to　271.8　±　16.2　MPa　in　the　vertical　direction,　representing　an　improvement　of　48　%　in　both　directions.　The　elongation　increased　by　44　%　and　32　%　in　the　horizontal　and　vertical　directions,　respectively.　However,　there　is　no　significant　relationship　between　the　change　in　elongation　and　the　amount　of　particles　added.　This　is　attributed　to　the　fact　that　the　increase　in　dot-like　precipitates　and　GBs　inhibits　crack　growth,　while　the　increase　in　pore　number　promote　it.　These　two　effects,　on　the　whole,　reach　a　certain　level　of　equilibrium.　©　2024