The emergence and development of modern brand theory originated from the United States after World War Ⅱ in the last century. It has gone through three stages:USP Theory, Brand Image Theory and Positioning Theory. Since it was introduced into China at the beginning of this century, it has been developing, integrating and systematizing in the practice of guiding Chinese commercial competition, thus forming a theoretical fusion of Positioning Theory as the leading and dominant theory, With Positioning theory as the dominant theory, USP Theory and Brand Image Theory as the matching and endorsement, this is the inherent logic of the development and integration of brand theory. In this paper, the use of brand theory in the advertising war of Guazi Used Cars and Renren Car is taken as an example to analyze the integration stage of this theory.