A self-locking and positioning device for a dental brace, comprising: a brace main body, an elastic piece, and an upper cover. Wherein, on the brace main body is provided with a track and a fixing slot, while on the elastic piece is provided with a positioning piece and a slot. The positioning piece is provided with a barb, while the upper cover slides and fixes into the brace main body through the track. Then, the barb of the positioning piece on the elastic piece will act against a block portion on bottom of said upper cover, to restrict movement of the upper cover, to lock automatically the upper cover into position. The dental brace is simple in construction and easy to assemble, hereby raising production efficiency and yield.