Ceramic photonic crystals have wide application potentials for THz technology due to their characteristic strong chemical stability and high temperature resistance for demanding environment. However, it is still a challenge to modulate the THz properties of as-prepared ceramic TPCs via post-creation treatments to satisfy different application requirements. In this work, the THz properties of rutile TiO2 ceramic 3D-TPCs were modulated by non-metal anion doping of either carbon or nitrogen, which was firstly created by the direct-writing technique with a TiO2 sol-gel ink followed by the high temperature sintering process at 1200 degrees C. Calcination of the pristine rutile TiO2 ceramic 3D-TPCs in either CO or NH3 atmosphere successfully doped either C or N dopants into rutile TiO2 ceramic 3D-TPCs, respectively, which changed their dielectric properties and subsequently induced different THz properties on these ceramic 3D-TPCs with the same structure. Their THz properties were found to be largely affected by the specific nature of the dopant. Compared with the pristine rutile TiO2 ceramic 3D-TPC, the bandgap positions of both C-doped and N-doped rutile TiO2 ceramic 3D-TPCs largely shifted toward the higher frequency, while the N-doped sample demonstrated a much broader bandgap. Thus, non-metal anion doping could be an effective post-creation approach to modulate the THz properties of ceramic TPCs.