Abstract: The academic circle has done a lot of research on the inheritance of national traditional sports from the perspective of "idealistic". However, little attention has been paid to the formation of "realistic" on the basis of "idealistic" or its occurrence logic.The "process-event" is taken as the analysis strategy to conduct an ethnographic study on the contradiction between the "realistic" and "idealistic" dimension of LT Village's Song-Jiang Battle Ritual's inheritance. It is found that the role transition between government departments and civilian elites, the action game between the civilian elites and government departments, and the evolution of the demands of the grassroots and civilian elites are the joint forces of unpredictable outcomes.The three-dimensional embedding of government, folk elites and grassroots, as well as the divergence between exogenous and endogenous motivation are the overall generation logic for the unintended consequence of the national traditional sports inheritance.Thereafter it is held that the actual situation of unintended consequence provides a new breakthrough point for the policy adjustment of national traditional sports' inheritance, and its continuous effect provides a reproductive channel for the policy formulation. The theoretical research and practical orientation of the inheritance of national traditional sports should stress process events from idealistic to realistic on the basic investigation, and recognize the actual state based on the empirical facts. Besides, the integration development of endogenous and exogenous motive force is proposed to build a hybrid power mechanism for the inheritance of national traditional sports.