Fatigue　test　of　a　needled　C/SiC　composite　with　a　notch　under　tension-tension　cyclic　loading　was　completed,　and　the　main　fatigue　crack　propagation　curve　of　the　needled　composite　was　obtained　by　the　in　situ　observation　of　the　fatigue　process.　By　analyzing　the　influence　of　the　failure　number　and　distribution　on　the　tensile　loading　subjected　by　0　degrees　fiber　bundles,　the　relationship　between　the　main　fatigue　crack　propagation　and　the　distribution　of　0　degrees　fiber　bundles　in　the　needled　composite　was　established.　By　observing　the　fracture　microstructure　(especially　the　distribution　of　0　degrees　fiber　bundles)　of　the　needled　composite　through　scanning　electron　microscopy,　the　reasons　for　the　varying　fatigue　resistance　of　different　notched　specimens　were　also　explained.　In　addition,　acoustic　emission　(AE)　was　also　used　to　analyze　the　AE　energy　characteristics　during　the　fatigue　crack　propagation　process　of　the　needled　composite.