Additive manufacturing is a revolutionary technology that offers a different pathway for material processing. High temperature anisotropic stress rupture properties of superalloy by additive manufactured is an urgent problem to be solved. In this study, Inconel 718 alloy cylindrical rods with their axes normal or parallel to the building directions were fabricated by selective laser melting (SLM). The microstructural design was achieved through Hot isostatic pressing (HIP) and heat treatment process parameter manipulation. The effects of different post-treatment on microstructure of the alloy were studied. In addition the mechanical properties of the vertical and horizontal samples were tested at room temperature, the stress rupture tests of the samples were conducted under a constant stress of 690MPa at 650℃.The mechanical properties of the samples after different post-treatment are quite different, especially for anisotropic stress rupture properties at high temperature. After the HIP + solution and double aging treatment, the normal temperature yield strength, tensile strength and elongation of vertical and horizontal samples are significantly improved, the samples with the best properties higher than those of wrought standard. Besides the high temperature stress-rupture tests time of vertical and horizontal samples with the best comprehensive stress rupture properties reach 184h and 123h respectively. We identified the correlation between microstructure and anisotropic stress rupture properties of the sample. Standard heat treatment can not be effectively eliminated columnar grains, which leads to the failure to effectively improve the stress rupture properties of horizontal samples, the large amount of needle-like δ phase in the grain caused by standard heat treatment promotes the nucleation of void-formed cracks. Hot isostatic pressing can effectively eliminate Laves phase and micropores in the deposited state, meanwhile it can homogenize the grains and promote the coordinated deformation capacity of grain size. The precipitation of γ′′, γ′ and twin-boundaries has a good strengthening effect on both horizontal and vertical samples.