The roles of Pd and Pt doping in penta-hexa-graphene (PH-G) were studied using first principles DFT calculations, which may lead to a better understanding of the dopant effects and further help to expand the application potential of PH-G. We find that doping could significantly change the basic properties in PH-CX (X = Pd, Pt). Compared to PH-G, doping transforms these materials from semiconductors into conductors, resulting in the emergence of Dirac points near the Fermi level. Considering spin-orbit coupling (SOC), the topological insulator (TI) PH-CPd (PH-CPt) emerges, characterized by a nonzero topological invariant (