Extreme　High-Speed　Laser　Metal　Deposition　(EHLMD)　is　an　efficient　additive　manufacturing　technology　that　can　quickly　form　difficult-to-machine　materials.　However,　the　rapid　melting　and　solidification　of　EHLMD　has　the　characteristic　of　forming　a　metastable　microstructure.　This　study　examines　the　effect　of　different　aging　temperatures　on　the　microstructure　and　properties　of　EHLMD　K648　superalloy.　It　is　found　that　the　formation　of　long　needle-like　alpha-Cr　phase　and　gamma＇　phase　at　lower　aging　temperatures　(750　degrees　C　and　800　degrees　C)　is　more　beneficial　for　improving　the　strength　of　EHLMD　K648　superalloy.　The　tensile　strength　was　highest　at　750　degrees　C　(1236　MPa)　but　its　elongation　was　low　(9.4　%).　As　the　aging　temperature　increased　(850-900　degrees　C),　the　alpha-Cr　phase　transformed　into　rods　and　small　particles,　resulting　in　a　decrease　in　tensile　strength　and　an　increase　in　elongation.　At　900　degrees　C,　the　tensile　strength　was　918　MPa　and　the　elongation　was　21.0　%.　With　further　increase　in　aging　temperature　(＞900　degrees　C),　coarse　carbide　and　alpha-Cr　phase　precipitated　in　EHLMD　K648　superalloy,　causing　its　tensile　strength　and　elongation　to　decrease.　When　the　aging　temperature　reached　1000　degrees　C,　the　tensile　strength　and　elongation　decreased　to　790　MPa　and　13.3　%,　respectively.