IN718 alloy exhibits excellent mechanical properties at high-temperature and good workability, it has been widely used in aircraft engine turbine disks, compressor disks, and power turbine shafts (i.e., rotating components). The mechanical properties of IN718 alloy, specifically, its creep and fatigue properties are a key factor determining the safety and reliability of engines. In this study, the effects of solution treatment at temperature ranging from 900 _oC to 1050 _oC on the microstructure and mechanical properties (including the tensile strength at room temperature and 650 _oC, the stress-rupture behavior at 650 _oC and 700 MPa, and the low-cycle fatigue behavior at 450 _oC) were systematically investigated. The results showed that in specimens subjected to solution treatment at temperature from 900 _oC to 990 _oC, the mass fraction of the d-phase decreases with increasing temperature,whereas the grain size remains the same. However, in specimens treated at temperatures ranging from 990 _oC to 1050_oC, the d-phase was dissolved and the grain size increased from 15 to 100 mm. With proper adjustment of the microstructure of IN718 alloy, this material exhibits a wider and superior range of performance to satisfy the requirements for fields that require high-temperature, corrosion-resistant, and radiation-tolerant materials, such as the aviation, petrochemical, and nuclear power industries.