Aimed　at　a　composite　fault　of　rotor　failure　and　weak　roller　bearing　fault,　a　fault　diagnosis　method　based　on　empirical　mode　decomposition　(EMD)　was　proposed　to　separate　the　coupling　features　of　the　composite　fault　and　to　extract　the　fault　feature　of　the　roller　bearing.　Signals　were　decomposed　to　obtain　several　intrinsic　mode　functions　(IMF)　by　EMD.　Main　components　are　confirmed　by　calculating　the　correlation　coefficient　of　every　IMF　and　original　composite　signal,　and　false　components　were　removed　at　the　same　time.　Finally　low-frequency　rotor　fault　feature　was　extracted　by　FFT　from　the　low-frequency　component　of　main　components,　and　high-frequency　modulate　feature　of　the　roller　bearing　was　extracted　by　Hilbert　envelope　demodulation　from　the　high-frequency　component　of　main　components.　Simulation　and　experiment　analysis　results　indicate　the　validity　and　the　practicability　of　the　method　proposed.