Significant　disturbances　are　imposed　on　the　altitude　test　facility　pressure　control　system　during　the　aeroengines＇　transition　state　tests,　which　degrades　the　control　performance　and　subsequently　reduces　the　accuracy　and　reliability　of　engine　tests　and　evaluation.　To　tackle　this　problem,　we　propose　the　utilization　of　an　active　disturbance　rejection　control　(ADRC)　based　controller.　Additionally,　we　introduce　a　particle　swarm　optimization　(PSO)　algorithm　to　optimize　and　fine-tune　the　parameters　of　the　ADRC　controller　for　the　simulation　system　of　intake　environmental　pressure.　Meanwhile,　a　component-level　modeling　approach　is　employed　to　establish　a　simulation　platform　for　altitude　test　facility　pressure,　and　proposed　method　is　validated　through　experiments　conducted　on　the　platform.　The　results　clearly　indicate　that　the　PSO-ADRC　significantly　improves　the　performance　of　pressure　control.　©　2023　IEEE.