Due　to　the　complex　nonstationarity　of　ground　motion　in　time-frequency　domain,　the　traditional　methods　of　comparing　and　evaluating　earthquake　waveforms　have　not　enough　ability　and　accuracy　to　distinguish　the　details　and　changing　features　of　the　similar　waves,　which　makes　the　similarity　evaluation　of　waveform　is　difficult　to　be　quantified　accurately.　The　similarity　degree　of　different　signals　can　be　calculated　precisely　according　to　dynamic　time　warping　(DTW)　algorithm,　so　it　can　be　used　for　waveform　comparison　and　similarity　evaluation.　In　order　to　improve　the　traditional　method,　a　method　based　on　DTW　distance　is　proposed　to　identify　the　earthquake　waveform　and　analyze　the　ground　motion　characteristics.　Based　on　the　statistical　analysis　of　a　great　quantity　of　earthquake　waves,　the　changes　law　of　DTW　distance　considering　amplitude,　time　lag,　noise　signal　ratio,　site　type,　and　the　comprehensive　effect　is　obtained.　DTW　distance　is　proved　to　be　used　as　a　compatible　evaluation　standard　for　waveform　refinement.　It　is　verified　that　DTW　distance　and　vector　norm　are　essentially　equivalent.　In　the　analysis　of　ground　motion,　DTW　distance　is　implicated　in　the　equivalent　amplitude　and　energy　of　earthquake　waves.　The　physical　connotation　of　DTW　distance　is　demonstrated　by　analyzing　the　data　of　the　station　array,　and　the　results　show　that　the　distribution　of　DTW　distance　can　accurately　imply　the　time-space　variation　effect　of　the　earthquake　in　the　region.　The　reasonable　reference　range　of　DTW　distance　is　defined　by　statistical　method,　and　the　corresponding　evaluation　standard　of　synthetic　multi-point　ground　motion　with　real　characteristics　is　proposed.　In　the　synthetic　accuracy　evaluation　of　artificial　ground　motion　with　spatial　variation　effect,　the　combination　of　ground　motions　with　more　real　characteristics　can　be　obtained　by　evaluating　and　optimizing　the　waveforms　according　to　the　variation　rule　and　range　of　DTW　distance.