Refractory　high-entropy　alloys　(HEAs)　have　excellent　mechanical　properties,　which　could　make　them　the　substitutes　of　some　superalloys.　However,　the　high　melting　point　of　refractory　HEAs　leads　to　processing　problems　when　using　traditional　processing　techniques.　In　this　study,　a　single　BCC　solid　solution　of　NbMoTaW　alloy　was　formed　by　selective　laser　melting　(SLM)　with　a　linear　energy　density　of　up　to　2.83　J/mm.　The　composition　distribution　was　analyzed,　and　the　element　with　a　lower　melting　point　and　lower　density　showed　a　negative　deviation　(no　more　than　5%)　of　the　molar　ratio　in　the　formed　alloy.　The　HEA　shows　an　excellent　microstructure,　microhardness,　and　corrosion　resistance　performance　compared　with　traditional　superalloys,　making　it　a　new　substitute　metal　with　great　application　prospects　in　aerospace　and　energy　fields.