Aiming　at　difficulty　of　weak　impactive　roller　bearing　fault　feature　extraction　of　composite　faults,　a　demodulation　method　based　on　the　second　generation　wavelet　and　the　empirical　mode　decomposition　(EMD)　is　proposed　to　separate　the　coupling　features　of　a　composite　fault　and　to　extract　the　fault　feature　of　a　roller　bearing.　Firstly　original　signals　are　decomposed　and　reconstructed　by　using　the　second　generation　wavelet.　Then　the　high-frequency　signal　from　decomposition　and　reconstruction　of　original　signals　is　analyzed　using　EMD,　several　Intrinsic　Mode　Functions　(IMFs)　are　obtained.　Then　the　high-frequency　components　of　IMFs　are　analyzed　by　Hilbert　envelop　demodulation,　the　modulate　fault　feature　is　extracted　exactly.　Simulation　and　experiment　analysis　results　indicate　the　validity　and　the　practicability　of　the　method　proposed　here.