The hot corrosion behavior of Ni‐based superalloys induced by NaCl at 600°C, 650°C, and 700°C in a marine‐like environment was investigated. The results show that the corrosion scale on the IN718 alloy includes two distinct layers, of which the outer layer is mainly composed of NiFe2O4 and NiO, while the inner layer contains FeCr2O4 and NiCr2O4. The HCl(g) as a catalyst significantly accelerated the corrosion of the samples. The formation of the Cr‐depletion layer was analyzed. The O2 in the atmosphere can diffuse to the substrate surface through the corrosion product layer, leading to internal corrosion. The hot corrosion behaviors of the corroded samples have been discussed in detail.