The coke solution loss reaction was investigated by using a well-type Si–Mo rod electric furnace. The effects of the CO2 flow rate, reaction time, loading mode, and loading amount of iron particles on the coke solution loss reaction were investigated. By comparing the SEM and EDS before and after the reaction of loaded iron particle coke, the reasons for the influence of loading mode on the coke solution loss reaction were explored, and the mechanism behind it was further explored. The experimental results show that there is a positive proportional relationship between the CO2 flow rate and reaction time with coke solution loss reactivity. The adsorption and addition of iron oxide play an important role in promoting the coke solution loss reaction, but when the saturation point of iron oxide loading is exceeded (1%), the adsorption load of iron particles has little effect on the coke solution loss reaction. At the same reaction temperature, the carbon conversion of the adsorption method is 10% larger than that of the addition method. From the analysis of SEM, it can be seen that the mechanism of iron particles affecting the coke solution loss reaction is different under the two loading modes. In the addition method, some iron particles are wrapped in a coke pore wall matrix, so they cannot play a role. In the adsorption process, iron particles are uniformly distributed on the coke surface, which provide more effective catalytic active centers. In addition, when iron particles are loaded by the addition method, they participate in coke formation, which affects the coke structure and then affects the coke solution loss reaction. The iron particles in the adsorption method play a catalytic role in the coke solution loss reaction.