Co-precipitation and hydrothermal synthesis method were used respectively to prepare Co-Mn-Ni-Mg-Fe-0 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-0 material. It is shown by the experiment that NaOH solution is the most suitable precipitator, and the most suitable temperature is 250°C for l0h. The nanocrystalline powder with a spinel structure is spherical and the average diameter is 75 nm, the special surface area is 64m2/g. The as-prepared powder is uniform in size and its well dispersed. In addition, the increase of reaction time improves the crystallinity of the material, but is doesn't change the particle size.