A structure of an SMD (surface mount device) diode frame is provided that comprises a plastic seat and a plurality of metal pins. One side of the plastic seat has a concave functional area and the other side of the plastic seat corresponding to the functional area has a plurality of concave reserved holes. The functional area and the reserved holes are respectively formed via a forming bolt and a positioning bolt in a mold. If the forming bolt and the positioning bolt abut against the metal pins respectively, the preciseness of the size of the functional area is increased and the overflow of the material of the plastic seat is decreased. Furthermore, the yield of the manufacturing processes is improved.