In this study, a novel and facile approach of catalytic graphitization was adopted for the preparation of graphitized polyacrylonitrile (PAN)-derived carbon. Pure PAN and boron-introduced PAN were derived from the monomer acrylonitrile using a polymerization technique. Iron nitrate nonahydrate at different concentrations (2.5%, 5%, and 10%) was added to the boronated PAN and carbonized at 1250 °C. The effect of iron and boron on the catalytic graphitization of PAN was comprehensively analyzed. The results showed that the boronated PAN containing a 5% Fe salt was more graphitized due to the optimized amount of the metallic iron, which promoted the rate of conversion of the amorphous carbon to graphitic carbon containing carbon nanotube (CNT) by rearranging the nearby carbon and reducing the energy barrier for the transformation. Furthermore, the in situ formed iron boron carbide within the graphitized carbon provided a nucleation site and stabilized the catalytic activity of the metallic iron at high temperature. This work presents a promising approach for obtaining a highly graphitic PAN-derived carbon by adopting a strategy of catalytic graphitization using the born and iron as catalytic agents.