Highly reactive ferro-coke has been widely studied due to its contribution to the energy saving and emission reduction in blast face ironmaking. To optimize the coking process of ferro-coke and improve its metallurgical properties, it is necessary to clarify the influence of initial iron ore on the strength, micro-morphology and CO2 gasification reaction behavior of formed ferro-coke. The effects of initial iron ore particle size (0.50–1.00, 0.25–0.50 and 0.074–0.125 mm) on the CO2 gasification reaction of ferro-coke were analyzed using thermo-analysis technique. In addition, the effects of initial iron ore particle size on the strength and morphology of ferro-coke were investigated by drum test, digital microscopy and scanning electron micro-scopy. The results show that iron reduced from iron ore has a great promotion effect on the CO2 gasification reaction of ferro-coke. The smaller the particle size of initial iron ore, the more intense the gasification reaction, and the lower the starting temperature for gasification reaction of ferro-coke. The results of kinetic calculation show that the apparent activation energy of ferro-coke decreases with the decreasing particle size of blended iron ore. The particle size of initial iron ore has a great impact on the strength of ferro-coke. The ferro-coke prepared by 0.25–0.50 mm iron ore presents the best strength in this experiment.