In　this　study,　Al-Zn-Mg-Cu　alloy　components　were　prepared　using　wire　arc　additive　manufacturing　(WAAM).　Through　multi-scale　characterisation　technology,　performance　testing　and　slow　strain　rate　tensile　(SSRT)　testing,　the　microstructure,　mechanical　properties　and　stress　corrosion　cracking　(SCC)　susceptibility　of　WAAM　Al-Zn-Mg-Cu　components　were　studied,　revealing　the　generation　mechanism　of　inhomogeneity　and　anisotropy.　The　results　show　that　with　the　increase　of　WAAM　thermal　cycles,　the　matrix　precipitates　(MPs),　grain　boundary　precipitates　(GBPs)　and　precipitation-free　zones　(PFZ)　evolve　in　different　paths　and　increase　to　varying　degrees,　resulting　in　performance　decrease　and　increase　in　stress　corrosion　susceptibility,　so　the　inhomogeneity　is　mainly　attributed　to　differences　in　precipitated　phases.　The　Inter-layer　inclined　to　the　scanning　direction　and　the　Inner-layer　inclined　to　the　building　direction　led　to　anisotropy　in　tensile　strength　and　SCC　behaviour,　so　the　anisotropy　is　mainly　attributed　to　the　grain　orientation　and　fracture　mode.