Abstract: Co-precipitation and hydrothermal synthesis method were used respectively to prepare Co-Mn-Ni-Mg-Fe-O compound NTC（negative temperature coefficient） thermistor material.The samples were tested by using XRD,SEM technology.The results show that hydrothermal synthesis is suitable for synthesizing Co-Mn-Ni-Mg-Fe-O material.It is shown by the experiment that NaOH solution is the most suitable precipitator,and the most suitable temperature is 250℃ for 10h.The nanocrystalline powder with a spinel structure is spherical and the average diameter is 75nm,the special surface area is 64m²/g.The as-prepared powder is uniform in size and it’s well dispersed.In addition,the increase of reaction time improves the crystallinity of the material,but is doesn't change the particle size.