The invention discloses a device used for detecting iron ore powder assimilation temperature with electric signals, and a detection method of assimilation reaction opportunity, and belongs to the field of iron ore powder sintering characteristic detection. The device comprises a heating unit, and a detecting unit; the heating unit is used for heating iron ore powder samples; the detecting unit comprises a temperature detection part and an electric signal detection part; the temperature detection part is used for detecting iron ore powder sample temperature; the electric signal detection part is used for detecting change situations of electric signals of the iron ore powder samples in temperature increasing process. In applications, iron ore powder samples are heated in the heating unit, the temperature detection part is used for iron ore powder sample temperature, the electric signal detection part is used for detecting change situations of electric signals of the iron ore powder samples in temperature increasing process, and iron ore powder assimilation temperature is detected via detecting the electric signal change in heating process, so that assimilation temperature detection accuracy can be increased.