The effect of Dazhu (BL 11) for gonalgia with flexion-extension dysfunction is remarkable, and its mechanism of action is interpreted as the influential point of bone treating bone diseases. However, through the exploration of a variety of literature, the relevant classical research, the views of senior experts, and combined with the author's experience, we put forward some new ideas and views for reference. Through in-depth analysis about pathogenesis of gonalgia with flexion-extension dysfunction and the functional attributes of Dazhu (BL 11), combining meridian tendons differentiation and myofascial meridians, we consider that Dazhu (BL 11), with its unique "location" advantage, plays the role of regulating multiple viscera, meridians, meridian tendons and myofascial meridians, which is the mechanism for gonalgia with flexion-extension dysfunction.