In order to explore the reasons for the difficulty in the dehydration of acidified crude oil，through reviewing the experiments on the influence factors of acidified crude oil dehydration in recent years and the existing acidified crude oil dehydration technology，demulsification mechanism of crude oil affected by pH value，temperature and solid particles was summarized，the adaptability of the dehydration technology was concluded. The thermal chemical settlement method is suitable for treating crude oil with viscosity and low moisture content. The significant practical application effect of ultrasonic demulsification dehydration of thick oil shows that it can be used as an auxiliary of thermal chemical settlement process for demulsification. The water washing can remove some solid particles and acidified slag and is suitable for pre-treatment before gravity settlement. The high frequency pulse electrodesiccation is efficient in dehydration of acidified oil and aging oil，which is suitable for fine dehydration treatment. The microwave demulsification is still under research，thus the demulsification mechanism would be further studied and the industrial practical effect need to be verified. Suggestions for future research on demulsification and dehydration processes of crude oil are also provided.