Fiber optic distributed acoustic sensing (DAS) based on phase sensitive time domain reflectometry can realize large-scale distributed acoustic detection, which has attracted the research attention in many application fields in recent years, such as oil and gas exploration, geological imaging, pipeline safety and perimeter security. In this paper, the sensing principle of fiber optic DAS is discussed, and the fading mechanism and performance bottleneck of single mode fiber DAS are analyzed. To solve these problems, the acoustic sensing mechanisms and performances of various scattering enhanced fibers are introduced. Furthermore, the recent technologies and applications of the microstructured scattering enhanced optical fiber-based DAS system are briefly reviewed, and the possible development directions of DAS technology in the future is prospected.