The DF series high pressure filter can be directly installed under the electromagnetic directional valve to remove or prevent the mechanical impurities mixed in the hydraulic oil and the colloid and asphaltene produced by the chemical change of the hydraulic oil from entering the electromagnetic directional valve,so as to prevent the instability or jamming of the valve core and the occurrence of faults such as excessive wear of the valve,and maintain the normal operation of the system.It is especially suitable for automatic control system and servo system.