Microwave　ablation　which　has　the　advantages　of　minimally　invasive　and　high-efficiency　was　more　and　more　used　into　a　number　of　areas　such　as　cancer　treatment.　when　the　tumor　diameter　is　less　than　3cm　the　ablation　effect　is　ideal,　but　for　larger　tumors　it　must　be　a　higher　ablation　time　and　a　higher　power　which　can　result　in　the　reduction　of　the　antenna　performance,　so　the　uncertainty　of　curative　effect　enhanced.　Therefore　the　study　uses　in　ex-vivo　bovine　liver　to　explore　the　performance　of　a　new　cluster-type　microwave　antenna　which　has　three　microwave　ablation　needles.　The　temperature　distribution　and　60　degrees　C　isotherm　which　can　decide　the　scope　of　the　effective　ablation　were　explored.　The　study　carries　out　with　net　power　of　40W,　60W;　ablation　time　was　5min,　10min,　15min,　respectively.　For　the　power　of　40W,　the　maximum　temperature,　area,　volume,　diameter　and　longitudinal　diameter　was　88.812　degrees　C,　9.0511cm(2),　7.917　cm(3),　2.902cm,　3.830cm,　respectively　with　the　ablation　time　5min　while　99.184　degrees　C,　19.043　cm(2),　50.936　cm(3),　3.794　cm,　5.835　cm,　respectively　with　the　ablation　time　10min　and　106.094　degrees　C,　25.627　cm(2),　81.655cm(3),　4.612　cm,　6.719cm,　respectively　with　the　ablation　time　15min.　For　the　power　of　60W,　the　maximum　temperature,　area,　volume,　diameter　and　longitudinal　diameter　was　100.047　degrees　C,　25.372　cm(2),　80.345　cm(3),　5.343　cm,　6.908　cm,　respectively　with　the　ablation　time　5min　while　108.863　degrees　C,　42.216　cm(2),　185.716　cm(3),　6.319　cm,　8.102　cm,　respectively　with　the　ablation　time　10min　and　110.219　degrees　C,　49.803　cm(2),　244.965　cm(3),　7.228　cm,　8.720　cm,　respectively　with　the　ablation　time　15min.　The　60　degrees　C　isotherm　was　ellipsoid-like.　Under　the　same　power,　the　60　degrees　C　isotherm　increase　with　ablation　time　and　at　the　same　time,　the　60　degrees　C　isotherm　increase　with　power,　too.　This　study　may　make　an　important　support　for　the　development　and　clinical　application　of　the　antenna.