The utility model discloses a composite set for grinding sticky tape is duplicated to roughness relates to the coarse measuring device of pipeline, including two spherical grinding heads, two grinding heads all have a circular tangent plane, the radius of circular tangent plane is less than the radius of sphericity of grinding head, two circular tangent plane mutually perpendicular, two circular tangent planes pass through the connecting rod and connect. The spherical grinding head efficiency of grinding of this device is good, and can effectively accomplish the measurement to the roughness of tubular product inner wall depths.