A new method of fault demodulation based on empirical mode decompositio n(EMD) and homomorphic filtering is put forward for the vibration signal featur e of mine gearbox. The faulty signal of mine belt conveyer gearbox can be deco mposed into several IMFs using EMD method, then the 7.0Hz modulated fault signal is extracted from the outstanding IMFs through the homomorphic filtering demodulation analysis. The research shows that the method based on EMD and homomorp hic filtering demodulation is very effective for gearbox fault diagnois.