Abstract: In order to study the force transmitting behaviors under the granular flow lubrication system, an experimental apparatus of granular lubrication medium sheared between the flat sliding friction pairs was developed. Using this experimental apparatus, the influence of the granular materials, granular size, velocity and humidity on the force transmission behaviors were researched. Besides, the experimental results mainly considered the measured normal force and the measured shear force, which was transmitted from bottom plate to the top plate via the granules. The study results show that the measured normal force and the measured shear force decreased with the increased shear velocity and the humidity, but increased with the increased granular size. Granular lubrication had better lubrication effect than the dry friction, and had better carrying capacity than the oil lubrication. The force transmitting paths under granular lubrication mainly depended on the force chains between the granular lubrication medium. The experimental results revealed the force transmitting mechanisms of granular flow lubrication and also provided a useful reference for the industrial application of granular flow lubrication.