The polycrystal material Li2Mo2O6 is prepared using solid phase firing method. By X-ray diffraction, IR and ESR spectra, we determined that the polycrystal material is composed of two phases: Li2Mo2O4 and MoO2. Molybdenum exists in MoO2 crystal phase in the form of Mo4+. The relationship between crystal interface and temperature is analyzed by AC complex impedance spectroscopy. The AC conductivity is measured and it is found that the ln(σT)-l/T curve consists of two straight and one curved segments. The conductivity is σ27℃=1.36×10-3(Ω·cm)-1,σ115℃=1.49×10-3(Ω·cm)-1,σ300℃=9.71×10-3(Ω·cm)-1,σ370℃=2.42×10-3(Ω·cm)-1. The activation energy is E1 = 0.043eV, E2 = 0.235eV, Eav = 0.76eV. The electronic conductivity σe is measured by Wagner method, σe27℃ = 2.24×10-5 (Ω·m)-1, σe300℃= 4.476×10-3(Ω·m)-1. It is proved that the material is a solid electrolyte at room temperature and a mixed conductor at 300℃.