In order to study the influence of solution treatment on the mechanical properties of INCONEL 625 components manufactured by micro-arc plasma additive, the samples of Inconel 625 alloy thin-walled components manufactured by additive were solution treated at 950℃, 1050℃, 1150℃ and 1250℃. The results show that with the increase of solution temperature, the degree of grain remelting increases continuously, and the growth orientation becomes disordered. The dislocation density gradually decreases and its distribution is concentrated in the grain boundary area. The precipitates gradually decrease, and the process of dissolution occurs. With the increase of temperature, the solution strengthening inside the structure improves the tensile strength, but the weakening of strain strengthening leads to the decrease of yield strength. At the same time, the weakening of Laves" resistance to dislocation slip improves the elongation of thin-walled members. After testing, the yield strength, tensile strength and elongation reached the best after solution treatment at 1150℃, and the corrosion resistance of thin-walled structure was significantly improved after solution treatment. This provides support for the optimization of mechanical properties of INCONEL 625 thin-walled components manufactured by micro-arc plasma additive manufacturing.