The　well　bottom　data　real　time　has　been　transmitted　through　mud　pulse　signal　in　Wireless　Measurement　Drilling(MWD).　The　ground　of　the　decoding　system　to　the　mud　pulse　signal　detection　and　identification　is　the　core　of　the　measurement　while　drilling.　However,　mud　fluid　channel　has　pump　noise　and　mechanical　vibration　noise　serious　effect　on　signal　transmission　and　identification.　The　paper　proposes　phase　characteristics　identification　algorithm　to　the　pulse　signal　identification　based　on　Manchester　modulation.　Field　test　results　show　that　this　algorithm　can　correct　recognition　of　mud　pulse　signal.　The　decoding　system　decode　process　is　simple,　practical,　and　has　high　reliability,　low　probability　and　can　meet　the　engineering　application　requirements.　©　2011　IEEE.