Proposed equivalent item extraction based on contradictory truth table logic function algorithm, gives details of the algorithm implementation process. Select the one with eight inputs, two outputs of the chip to work waveform genera Test. Test results show waveforms attribute recognition model designed in this paper correctly identified the properties of the seven pins, re-use automatic correction algorithm, the successful implementation of misidentification pin Correction properties, complete all ten waveforms attribute recognition. KEYWORD: logic function extraction; attribute identification; algorithm; self-correction