Abstract: The purpose of this paper was to study the properties of powder-gas flow lubrication. An air compressor and oil-water separator were used to provide the high pressure dry air for the experimental equipment which was employed to transport powder-gas mixed flow to the tribo-pairs of a ring-block through a powder fluidization equipment. A series of lubrication experiments with the graphite powder as lubricant was performed based on Timken friction and wear tester. The results show that the device could provide stable and sustainable powder-gas mixed flow. The graphite powder-gas mixed flow injected into the tribo-pairs of a ring-block can make it keep good line contact and have a good lubrication function. Friction coefficient is below 0.1 while load is up to 450 N, and decreases with increasing of load. Fricition force increases with the increse of load, but is relatively small. The wear is also relatively small, and wear track of the block presents fine strips. When passing the tribo-pairs of a ring-block, the graphite powder-gas mixed flow convert the friction between surfaces of ring and block into the friction between graphite particles，and most heat is taken away by means of the air current, thus the temperature of tribo-pairs is decreased effectively.