The invention discloses a desert air filtering device. The device comprises a shell, a coarse filter, a plurality of vortex tubes, a plurality of cyclone separators, a fine filter and a sand discharging device. The filtering process is divided into coarse filtration, primary filtration, secondary filtration and fine filtration, the inlet air of an engine passes through the coarse filter, so that sundries with larger size are separated, and the tangential speed of the air is generated under the driving of primary filtration(the vortex tubes) inner flow guide vanes, gravel in the airflow is separated to the inner wall of the vortex tubes under the action of centrifugal force and is discharged out of the primary filtration from the two sides of the inner wall, and clean air enters the secondary filtration device cyclone separators from a middle channel, and finally flows through a fine filtration element to enter an engine air inlet pipe. Through the four processes, the problem of poor separation efficiency of a traditional desert air filter is effectively solved.