The Late Permian coal-accumulating area in northwestern Guizhou is an important coal-forming area in south China. So it is necessary to strengthen the geological research and to clear sequence stratigraphic framework as soon as possible. Compared with the traditional methods of using the core and logging data to divide the sequence with many subjective human factors，the wavelet transform technique has advantages of dividing sequence stratigraphy quantitatively. The relationships of sequence structure in northwestern Guizhou with time frequency energy spectrum and wavelet curve were analyzed to build up the wavelet transform models of transgressive system tract and highstand system tract of the study area.The energy clusters in the transgressive system tract gradually increased from deep to shallow，and moved from small scale to large scale；the energy clusters in the highstand system tract gradually decreased from deep to shallow，and moved from large scale to small scale. The third-order sequence was divided according to the sequence interface recognition results，the features of wavelet curves and the variation of time-frequency energy spectrum. Finally，the coal measure strata of Longtan Formation in the study area were divided into 4 third-order sequences and 8 system tracts，and each sequence was composed of transgressive system tract and highstand system tract while the development of lowstand system tract was not obvious. The division results show that the sequence boundaries defined by wavelet transform are consistent with those defined by the traditional methods.