The key equipment in the reprocessing industry, such as dissolvers and evaporators, have continually serviced in boiling nitric acid with high concentration and high radioactivity. Ensuring the safe and reliable operation of the equipment is the primary goal. This article investigated the effect of heat treatment process on the corrosion behavior of Ti-5Ta-5V-8Cr-1Al alloy (Ti5581) in 6mol/L boiling nitric acid solution using full immersion corrosion and electrochemical corrosion experimental methods. The results indicated that Ti5581 alloy has a lower corrosion rate under solid solution only process and 460 ℃ aging process, the corrosion rate was 0.022mm/a after 240 hours corrosion. Further analysis was conducted using metallographic microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and other analytical methods to analyze the structure and composition of the passivation film in the surface layer of Ti5581 alloy after corrosion. After corrosion, the surface passivation film was smooth and dense, and the surface passivation film was composed of a mixed oxide of Ti and Ta. Formation of passivation film in the surface layer of Ti5581 alloy was related to quantity and morphology of α phases. Compared to 550 ℃ aging process, the size of α phase was smaller and the mass fraction of Ta was higher in 460 ℃ aging process, which resulting in better corrosion uniformity and passivation film stability.