Abstract: With the application of all kinds of deep learning generation models in various fields, the authenticity of their generated multimedia files has become increasingly difficult to distinguish, therefore, deepfake technology has been born and developed. Utilizing deep learning related techniques, the deepfake technology can tamper with the facial identity information, expressions, and body movements in videos or pictures, and generate fake voice of a specific person. Since 2018, when Deepfakes sparked a wave of face swapping on social networks, a large number of deepfake methods have been proposed, which had demonstrated their potential applications in education, entertainment, and some other fields. But at the same time, the negative impact of deepfake on public opinion, judicial and criminal investigations, etc. can not be ignored. As a consequence, more and more countermeasures have been proposed to prevent deepfake from being utilized by the criminals, such as the detection of deepfake and watermark. Firstly, a review and summary of deepfake technologies of different modal types and corresponding detection technologies are carried out, and the existing researches are analyzed and classified according to the research purpose and research method. Secondly, the video and audio datasets widely used in the recent studies are summarized. Finally, the opportunities and challenges for future development in this field are discussed.