At　present,　wavelet　transform　applied　to　the　establishment　of　three-dimensional　rough　surface　datum　was　mainly　the　first　and　the　second-generation　wavelet.　However,　they　had　some　defects　such　as　the　shift　variation　and　poor　directional　selectivity　and　so　on,　especially　the　selection　of　optimum　wavelet　base　and　the　determination　of　the　times　of　wavelet　decomposition,　which　was　always　the　difficult　points　of　surface　evaluation.　Now　the　third　generation　wavelet　DT-CWT　was　used　for　valuation　of　three-dimensional　rough　surfaces,　by　comparing　the　datum　errors　and　maximum　reconstruction　error　of　the　actual　reconstruction　images　of　the　three　wavelets　as　well　as　simulation　of　three-dimensional　rough　surface,　the　optimality　of　DT-CWT　was　obtained.　Band　energy　method　was　employed　to　ascertain　the　times　of　wavelet　decomposition　and　then　mean　square　error　S　which　was　the　characterization　parameter　of　three　dimensional　simulation　surfaces　was　used　to　check　the　correctness　of　decomposition　times.　Finally,　the　reference　surface　of　the　three　dimensional　nonstationary　random　rough　surface　with　fractal　properties　was　extracted　by　DT-CWT　transform.　The　results　prove　the　effectiveness.