With the development of autonomous and intelligent attack technologies, the situation of cybersecurity is becoming increasingly severe, the traditional defense system can no longer meet the current security requirements. To reverse the passive situation of the network defese, the moving target defense(MTD) emerges as the time required. MTD increases the uncertainty, randomness, and diversity of network and system to resist the same type of attack, and greatly decreases the success rate of attack by effectively reducing its certainty, similarity, and static. At present, the vulnerability of MTD has not been systematically analyzed, and the specific application of MTD in new scenarios has not been summarized. Firstly, the background and basic theoretical knowledge of MTD are illustrated. Secondly, the research related to MTD is reviewed and the vulnerability of MTD is summarized. Then, we introduce how MTD could be applied to emerging fields such as cyber-physical systems, cloud environments, smart grids, and the defense of adversarial examples. Finally, the research prospects of MTD are analyzed. Through the review of this paper, the possible research directions of MTD are as follows: the analysis and improvement of the vulnerability of MTD, the promotion and development of the application in new scenarios of MTD, the precise evaluation and adaptive strategy optimization methods of MTD, the swift deployment of the large scale of MTD technology.