Due to the advantages of large aspect ratio, agile motion and flexible operation, hyper redundant robots have shown important applications for working in narrow spaces, such as aerospace manufacturing and high-end equipment. However, the design, modeling and control methods of traditional industrial robots are no longer applicable for hyper redundant robots because of their redundant degrees of freedom, resulting serious challenge for hyper redundant robots. In this paper, we review the hyper redundant robots for detecting and clearing complex narrow spaces, and the structure design, kinematic modeling, control method and motion planning of existing hyper redundant robots are summarized, respectively. Finally, future work of hyper redundant robots are prospected.