The　printability　of　Al6SiMg0.5Er1.0Zr　alloy　at　various　laser　power,　scan　speed,　and　hatch　spacing　was　investigated.　The　optimal　processing　window　was　determined.　The　relationship　between　hatch　spacing　and　lack　of　fusion　(LOF)　defects　and　microstructure　is　discussed.　Hatch　spacing　significantly　affects　the　cellular　size,　which　is　formed　by　eutectic　Si　network,　and　medium　hatch　spacing　can　achieve　the　finest　microstructure.　Samples　with　high　densities　and　fine　microstructures　were　investigated　more　carefully.　The　grain　and　cellular　boundaries　have　many　Al3(Er,Zr)　phases.　The　grain　size　was　refined　to　2.64　mm,　and　the　epitaxial　growth　of　columnar　crystals　was　completely　suppressed.　The　cellular　structure　has　been　significantly　improved.　Get　the　equiaxed　-　ultrafine　equiaxed　-　columnar　multi-cellular　structure　with　dramatically　enhanced　mechanical　properties.　The　yield　strength,　tensile　strength,　and　elongation　were　373　Mpa,　480　MPa,　and　5.5%,　respectively.　Grain　boundary　strengthening　and　Orowan　strengthening　was　the　main　strengthening　mechanisms.　&　COPY;　2023　The　Author(s).　Published　by　Elsevier　B.V.　This　is　an　open　access　article　under　the　CC　BY-NC-ND　license　(http://creativecommons.org/licenses/by-nc-nd/4.0/).