The distribution pattern of Shear stress at the first and second interfaces of the bolt was tested indoors by using three surrounding rock media of high, medium and low strength. On this basis, the interaction between the first and second interface Shear stress of the bolt is analyzed. It is pointed out that the Shear stress of the second interface is the result of the attenuation of the Shear stress of the first interface; The Shear stress of the first and second interfaces attenuates along and perpendicular to the axis of the bar, and there is a phenomenon that the ultimate Shear stress, zero Shear stress and local failure of the slurry basically transfer to the depth of the bar at the same time; It is emphatically pointed out that the theoretical basis of the average Shear stress the theory of the microstructure of the bolt interface is irrefutably misleading