Divided injection molding method and device thereof capable of preventing appearance defects caused by additional structures such as ribs or bosses on the back surface of a molded article main body

The present invention provides a divided injection molding method, which can prevent appearance defects caused by additional structures such as ribs or protrusions on the back surface of the molded article main body when injection molding is carried out by using an injection molding composition containing metal particles, thereby greatly improving the appearance characteristics of the molded article. The divided injection molding method includes: a first injection molding step of closing an molding unit and injecting an injection molding composition into a first forming unit from an injection unit for performing one injection molding; a molding unit rotating step of opening the molding unit and rotating the molding unit to switch the positions of the molds of the first forming unit and a second forming unit; a second injection molding step of closing the rotated molding unit, injecting the injection molding composition into the first forming unit and the second forming unit from the injection unit for sequent