Abstract: In order to better implement diret evaluation method of pipeline internal corrosion, the internal corrosion direct assessment standard for multiphase flow pipeline(MP-ICDA)proposed by National Association of Corrosion Engineers (NACE) in 2016 was researched from the aspects of application method and process and its reliability was detected. Based on the actual working conditions of one certain subsea multiphase pipeline in China, an internal corrosion prediction model was established according to the theory of multiphase flow. Then, in combination of high temperature and high pressure reactor experiments and electrochemical experiments, MP-ICDA was successfully applied to the multiphase flow pipeline. It is shown that the corrosion risk is higher at the ascending section of pipeline in the lower region and the inhibitor has a good inhibiting effect on the internal corrosion of subsea pipeline. The experimental results are basically consistent with the prediction results of the internal corrosion prediction model, indicating the reliability of the prediction model. In conclusion, MP-ICDA can be used as the guidance for predicting the location and risk of pipeline corrosion and provide the decision-making basis for pipeline integrity management in China.