Aiming at lack of effective algorithm for image gray feature wave analysis, this paper proposes a new local extreme extraction for image gray feature, which can establish full information of image feature wave for continue analysis. Firstly, the definition of image gray feature wave is given. Secondly, methods of local extreme extraction of feature wave are detail described, and specific calculation formulas are given. Finally, some examples of local extreme extraction of different fabric images are listed. Results show that this method is fast and easy, can exactly judge local extreme of feature wave, and lay a good foundation of data for continue image analysis and recognition.