To　study　the　forming　rule,　microstructures　and　mechanical　properties　of　Al-Zn-Mg　alloy　samples　produced　by　wire　+　arc　additive　manufacturing　(WAAM),　a　metal　inert　gas　(MIG)　arc　was　used　as　the　heat　source　and　1.2-mm-diameter　Al-6.2Zn-2.2Mg　welding　wires　were　used　as　the　raw　materials　during　single-pass,　single-layer　deposition　and　single-pass,　multilayer　deposition.　In　the　single-pass,　single-layer　deposition,　as　the　heat　input　increased,　the　number　of　ripples　on　the　weld　bead　decreased,　thereby　making　the　surface　smoother.　Furthermore,　under　different　parameters,　there　were　always　pores　in　the　cross-section　of　the　weld　beads.　In　the　as-deposited　material,　the　elements　were　unevenly　distributed　due　to　the　layer-by-layer　deposition.　There　were　two　types　of　pores　in　the　as-deposited　material:　pores　caused　by　the　presence　of　hydrogen　and　those　caused　by　the　burning　loss　of　zinc.　The　as-deposited　material　exhibited　an　average　hardness　of　112　HV.　The　horizontal　test　samples　exhibited　an　average　tensile　strength　of　324　MPa,　a　yield　strength　of　208　MPa,　and　an　elongation　of　9.66%.　The　vertical　test　samples　exhibited　an　average　tensile　strength,　yield　strength　and　elongation　of　299　MPa,　188　MPa　and　8.98%,　respectively.　Moreover,　the　samples　exhibited　mixed　ductile-brittle　fractures.　©　2020　The　Authors.