The　mechanical　properties　of　Al-Zn-Mg-Cu　alloys　produced　via　wire　arc　additive　manufacturing　(WAAM)　are　often　weakened　by　the　presence　of　continuous　and　coarse　precipitated　phases,　which　significantly　limits　their　practical　applications.　In　this　study,　high　-entropy　alloy　(HEA)　particles　were　incorporated　into　Al-Zn-Mg-Cu　alloy　during　the　WAAM　process,　which　inhibits　the　continuity　of　precipitated　phase,　and　the　mechanism　of　microstructure　evolution　and　macroscopic　mechanical　properties　optimization　of　the　components　are　explored.　The　results　show　that　HEA　particles　promote　grain　refinement,　and　disrupt　the　formation　of　continuous　precipitated　phase　along　the　grain　boundary　by　generating　plenty　of　fine　spot　-like　precipitated　phases,　thus　inhibiting　grain　boundary　segregation.　The　spot　-like　precipitated　phases　are　connected　via　a　slender　second　-phase　-band.　The　primary　precipitates　include　the　metastable　eta＇,　stable　eta,　and　T　phases,　and　the　diffusion　of　solute　atoms　forms　the　Al　3　Ni　and　Al　3　(Ni,　Cu)　2　phases.　The　tensile　strength　increases　from　247.4　+/-　5.9　MPa　to　326.2　+/-　19.7　MPa　in　the　horizontal　direction　and　from　273.0　+/-　13.7　MPa　to　335.4　+/-　11.1　MPa　in　the　vertical　direction,　which　correspond　to　increases　of　31.9　%　and　22.9　%　respectively.　The　enhancement　of　mechanical　properties　is　mainly　attributed　to　Hall-Petch,　Orowan,　load　-transfer,　solid　-solution　and　dislocation　strengthening　mechanisms.　Only　slight　variation　occurred　in　the　elongation,　the　increased　number　of　fine　spot　-like　precipitated　phases　and　grain　boundaries　hinder　the　crack　propagation,　while　the　increased　number　of　pores　facilitates　the　crack　propagation,　and　these　effects　almost　balance　each　other　out　in　competition.　These　findings　are　expected　to　provide　new　insights　into　the　microstructure　optimization　of　WAAM　components,　thereby　meeting　more　practical　applications.