A self-locking and positioning device for a dental apparatus, comprising: a main body (10) of the apparatus comprising a track (102) and a fixing slot (104), in which both sides within said track (102) of said main body (10) of the apparatus respectively comprise a slit portion (106), in which a reception space (108) is formed under said two slit portions (106)； an elastic part (14) comprising a positioning part (144) and a groove (142), in which one end of the positioning part (144) is connected to the groove (142), while the other end of said positioning part (144) is folded into a tongue form, in which the groove (142) of the elastic part (14) is arranged in the fixing groove (104) of the main body (10) of the apparatus and the positioning part (144) of said elastic part (14) is placed in said reception space (108) below the track (102) '', in which the groove (142) is configured to pass an arc (16 ) wire through it； and an upper cover (12), in which both sides of said upper cover (12) each comprise a strip-shaped protrusion portion (122), wherein said two protrusion portions (122) of said cover ( 12) upper can slide inside said main body (10) of the apparatus along said two slit portions (106) of the track (102), in which, when the upper cover (12) slides in the main body (10) of the apparatus along the track (102), the upper cover (12) is located above said positioning part (144) and said slot (142) with the hole (124) for fixing the upper cover (12) that is located just above the groove (142) and is engaged by means of the barb, so that the positioning part (144) of the elastic part (14) is fixed to the lower part of the upper cover (12) to automatically lock the elastic piece (14) and fix the upper cover (12) on the body (10) p The main device, in which the wire arch (16) that can be placed in the groove (142) at the time the upper cover (12) is opened, is fixed in the groove (142).Un dispositivo de autobloqueo y posicionamiento para un aparato dental, que co
