The invention discloses an automatic shaping device and an automatic shaping method of a W-shaped necklace buckle. The automatic shaping device comprises a template, a feeding mechanism, a first mold core, a cutting and bending die, an extrusion die, a second mold core and a third mold core, wherein the feeding mechanism is arranged at one side of the template, the first mold core is arranged on the template, the cutting and bending die is arranged above the first mold core, the extrusion die is arranged just below the first mold core, and the second mold core and the third mold core are arranged at the left side and the right side between the first mold core and the extrusion die; the template is provided with a first left outer die and a first right outer die at the left side and the right side of the first mold core and is also provided with a second outer die and a third outer die. The invention also discloses the automatic shaping method of the W-shaped necklace buckle. In the device, a mechanized structure is adopted so as to realize automatically feeding, cutting, bending, blanking and the other working procedures of the necklace buckle, thus, the yield is increased by multiple times as compared with the original manual operation and the shape of each necklace buckle conforms to the dimension standard because a mechanical mould is used for extruding and shaping. The device and method not only can be used for automatically shaping the necklace buckle but also can be used for the bending and shaping technology of the W-shaped small linear objects.