The　sensor　array-based　guided　wave　focusing　detection　method　can　effectively　improve　the　detection　sensitivity　of　defects　and　realize　the　visual　imaging.　In　this　research,　the　three-dimensional　finite　element　simulation　model　of　stainless　steel　pipeline　for　guided　wave　focusing　detection　was　established,　and　the　L(0,　2)　mode　of　guided　wave　was　excited　by　applying　a　load　on　the　end　surface　of　the　pipeline.　And　in　the　experiment,　the　excitation　and　reception　of　L(0,　2)　mode　guided　waves　on　the　outer　surface　of　the　stainless　steel　pipeline　were　realized　by　the　piezoelectric　transducer　array.　A　16-channel　guided　wave　focusing　experimental　system　was　integrated　to　conduct　the　defect　detection　experiments　on　a　stainless　steel　pipe　with　diameter　of　140　mm　and　wall　thickness　of　5　mm.　The　total　matrix　data　acquisition　was　performed,　and　then　the　amplitude　total　focusing　(TFM)　imaging　and　sign　coherence　factor　(SCF)　imaging　of　the　pipe　were　realized.　In　this　way,　the　experimental　results　showed　that　the　pipeline　defect　detection　method　and　the　system　proposed　in　this　research　can　achieve　the　longitudinal　and　circumferential　positioning　and　imaging　of　defects,　like　holes　and　scratches.