In　recent　years,　the　nonlinear　load　of　the　industry　is　increasing　with　the　development　of　the　power　electronic　technology.　The　harmonic　distortion　is　getting　more　and　more　serious.　So　measurement,　analysis,　and　restraining　the　harmonic　of　power　system　have　become　an　important　topic　for　the　environmental　management　of　the　power　system.　This　paper　presented　a　novel　method　to　analyze　power　harmonic　using　wavelet　transform,　and　researched　the　technology　how　to　detect　and　treat　the　harmonic　in　the　power　grid.　The　performance　applying　the　wavelet　method　to　detect　harmonic　from　experimental　signals　was　presented.　The　simulation　results　showed　that　wavelet　transform　can　extract　power　harmonic　in　different　frequency　from　the　signal　effectively.　©　(2012)　Trans　Tech　Publications,　Switzerland.