Regenerated fiber Bragg grating (RFBG) is prepared from an ordinary fiber Bragg grating (FBG) through a high temperature annealing process, which has a high temperature resistant. The RFBG can work under a high temperature environment since the grating degeneration does not exist in RFBG. RFBG has attracted much attention due to its easy fabrication process, low cost, and excellent sensing performance. We review the development of RFBG from formation mechanism, fabrication, regeneration of specific FBG, and mechanical strength protection and forecast the high temperature sensing applications of RFBG.