The　dynamic　analysis　of　the　750Kw　wind　turbine　blade　was　presented　based　on　Reverse　Engineering.　Because　of　complex　shape,　the　model　of　wind　turbine　blade　is　a　bottleneck　of　restriction　development　on　the　dynamic　characteristic　research　of　blade.　The　work　attempted　a　new　way　to　build　the　blade　3D　model　and　completed　the　dynamic　analysis.　At　first,　the　point　cloud　data　of　blade　were　gained　using　ATOS　optical　scanner.　Secondly　simplified,　smoothed　and　partitioned　in　Imageware,　point　cloudy　data　were　created　into　curves.　Then　the　curves　were　imported　into　UG,　the　3D　model　of　blade　was　attained　through　curve　fitting.　At　last　the　dynamic　analysis　of　the　blade　was　completed　in　ANSYS　Workbench.　The　analysis　adopted　BlockLanczos　method　to　extract　the　mode　and　get　the　natural　frequency　and　eigenmode　from　the　first　to　sixth　modes.　The　paper　ascertained　the　first　and　second　wave　eigenmodes,　the　first　swing　and　the　first　torsion　eigenmode.　Calculations　showed　that　eigenvalue　of　wave　vibration　and　swing　vibration　were　lower,　torsion　vibration　eigenvalue　was　higher.　In　the　vibration　of　the　blade,　the　couple　vibration　of　wave　and　swing　taked　major　role,　and　the　influences　of　torsional　vibration　were　not　great.　The　results　showed　the　wave　and　swing　vibration　were　predominated,　the　torsional　vibration　can　be　neglectful.　The　paper　developed　some　new　methods,　established　foundations　for　the　further　research　of　large　wind　turbine　blade　in　the　future.　©　(2011)　Trans　Tech　Publications.