One problem associated with ironmaking is the depletion of carbonaceous material (e.g., coal) for iron reduction. A combination of coal and biomass (coal biomass co-pyrolysis) provides an advantageous synergetic effect to overcome the disadvantage of using renewable raw materials, such as biomass. In this study, we investigated the effect of coal biomass co-pyrolysis in integrated pyrolysis tar decomposition over low-grade iron ore. Combined coal biomass with biomass blending ratios (BBRs) of 0, 25, 50, 75, and 100% were studied by thermogravimetric analysis. A kinetic study on the co-pyrolysis using a double-distributed activation energy model has been conducted. Coal biomass co-pyrolysis was also performed in integrated pyrolysis tar decomposition over porous iron ore. The reference line method was used to identify the synergetic effect for each pyrolysis product. A synergetic effect of coal biomass co-pyrolysis has also been found for decreasing char and heavy tar products as well as for increasing light tar, gas, and deposited carbon through chemical vapor infiltration (CVI) over porous iron ore. The highest carbon content of CVI ore (4.70%) was obtained when using BER-25%.