By using HeXie Mechanism guided by HeXie Theme(HT), Efficiency being integrated with customer responsiveness helps to build competitive advantage. The “relative certainty →uncertainty →relative certainty” pattern of thinking and “trial and error” way of acting have the intrinsic uniformity, so the problem of slow response is resolved through the combination thinking and action by HeXie Management. Based on this, we explore that the competitive advantage building on HeXie Management is sustained under demand fluctuation environment, and use Toyota as a case to illustrate the theoretical thought. Thus, to unify HeXie Management's general principle with the specific phenomenon/question in practice and its mechanism helps people find ways to build sustained competitive advantage in the shrinking demand environment.