Thewaveletpackettransformisusedforthedamagedetectionofoffshoreplatforms.Whensomedamageoccurs,thedynamicresponseparametersofthestructurewillshiftsubtly.However,insomecases,thedynamicparameters,suchasdynamicresponse,arenotsensitive,anditisverydifficulttopredicttheexistenceofdamage.Thepresentpaperaimstodescribehowtofindsmalldamagebytheuseofwaveletpackettransform.Asthewaveletpackettransformcanbeusedtoquicklyfindthesingularityoftheresponsesignalondifferentscales,theaccelerationsignalofadamagedoffshoreplatforminthetimedomainistransformedthroughthewaveletpacket.ExperimentalresultsshowthattheDaubechies4wavelettransformcanbeusedtodetectdamage.