Abstract: Resistance in iron ore undergoes a sharp change of up to several orders of magnitude when the sintered solid phase changes to liquid phase. In view of the insufficiency of existing assimilation detection methods, a timing-of-assimilation reaction is proposed, which was judged by continuously detecting the changes in resistance at the reaction interface. Effects of pole position and additional amounts of iron ore on assimilation reaction timing were investigated. The results showed that the suitable depth of pole groove was about 2 mm, and there was no obvious impact when the distance of the poles changed from 4 to 6 mm, or the amount of iron ore changed from 0.4 to 0.6 g. The temperature of sudden change of resistance in the temperature-resistant image was considered to be the lowest assimilation temperature of iron ore. The accuracy of this resistance method was clarified by X-ray diffraction, optical microscope, and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) analyses.