Abstract: Inconel 738 alloy was formed by selective laser melting technology. The effects of solution treatment and aging on the microstructure and mechanical properties of Inconel 738 alloy were investigated. The results show that with the increase of solution temperature, the amount of coarse primary γ′ phase decreases and the amount of fine secondary γ′ phase increases. With the increase of solution temperature, the microhardness of the solution+aging treated samples gradually increases from 438.0HV to 481.1HV. The tensile test at room temperature showed that the longitudinal and transverse tensile strength of the as-deposited samples were 1199.65 MPa and 1257.39 MPa, respectively, and increased to 1292.91 MPa and 1283.31 MPa after heat treatment. The longitudinal and transverse elongation after fracture of the sample after heat treatment increased from 14.39 % and 7.67 % of the deposited state to 27.83 % and 22.23 %, respectively. The high temperature tensile properties test at 900 °C showed that the tensile strength of the longitudinal sample decreased from 781 MPa to 610 MPa and the elongation increased from 4 % to 18 % after solution + aging treatment. The tensile strength of the transverse specimen decreased from 674 MPa to 598 MPa, and the elongation increased from 0.5 % to 5.5 %.