The work aims to analyze the failure behavior and cause for the leaking problems of tube bundle during the pro-duction process of reboiler and then provide theoretical basis for the failure control of such reboiler. Based on production standards and service conditions of the faulty tube bundle, material properties, corrosion mechanism and flow and temperature distribution characteristics were analyzed through chemical composition analysis, metallographic structure analysis, corrosion products analysis and finite element analysis. From the physiochemical test results, the chemical composition of tube bundle was in conformity with relevant standards, and no abnormality was detected in metallographic structure. However, a layer of loose corrosion products was accumulated at the perforated outer wall and the chemical elements included C, O, S, Fe, and a small amount of Cl. Besides, the main phase compositions were Fe3O4, Fe2O3, FeCO3 and CaSO4. Based on the result of finite element simulation of flow distribution, the flow rate of condensate oil in shell side was generally low and there was fluid retention phenomenon (about 1.5×10-4 m/s). In addition, a local high-temperature zone (about 105~112 ℃) on the shell side was found according to finite element simulation of temperature distribution. The failure behavior of the reboiler tube bundle is serious local CO2 corrosion caused to the outer wall of tube bundle in local high-temperature and fluid retention areas. The Cl- with high concentration penetrates corrosion product film (FeCO3) and promotes pitting corrosion, thus ultimately leading to external corrosion perforation and leaking problem.