It is well known, asks the function the most value is one of middle school mathematics important contents. Asks the law about the function most value, is in the high school mathematics teaching difficulty and key, is one which of contents all previous years college entrance examination inspects. But asks the function most value the method is also many and varied, presents “the application to be widespread mostly, the solution is flexible” the characteristic, it involves the aspect of knowledge is broad, problem solving skillful, method also because of topic, but different. But asks the function in the present high school teaching material the most value arrangement related content not to make specially said that actually in the high school mathematics teaching, the exercises, and even the high school graduation meets in the examination question and the high examination question, everywhere may meet asks the function most value the question. Therefore, we have the necessity to ask the function most value the method to make the full induction and the understanding. This article on the high school mathematics's request, has done the related research to the function most value question, summarized induces the solution function most value general method, discussed when the solution function most value should pay attention the question, elaborated through the above question, raises student's mathematics application consciousness, sharpened student's mathematics modelling ability and problem solving ability as well as innovative idea ability.