With　strong　nonlinearity，　high　uncertainty　and　strong　external　disturbance　for　flight　altitude　simulation　of　altitude　test　facility，　a　robust　cascade　linear　active　disturbance　rejection　control　(LADRC)　algorithm　via　the　reduced　order　linear　extended　state　observer　(RLESO)　was　proposed.　In　particular，　the　main　characteristics　and　control　issues　of　the　controlled　plant　were　analyzed，　and　the　generalized　controlled　plant　can　be　included　by　the　butterfly　valve　position　loop　and　flight　altitude　loop.　The　RLESO　and　corresponding　controller　were　designed　for　the　two　loops　respectively，　meanwhile　the　cascade　control　system　was　constructed.　The　robust　cascade　LADRC　was　realized　in　the　simulation　environment　and　compared　with　the　classical　PID　control　scheme.　When　the　engine　was　subject　to　the　thrust　transient　test，the　maximum　fluctuation　value　of　the　controlled　pressure　was　reduced　from　3.5　kPa　to　0.8　kPa.　This　indicated　that　the　robust　cascade　LADRC　technology　via　RLESO　can　significantly　improve　the　dynamic　control　quality.　The　ideal　robust　control　performance　and　anti-disturbance　ability　for　flight　altitude　simulation　were　obtained.　©　2024　Beijing　University　of　Aeronautics　and　Astronautics　(BUAA).　All　rights　reserved.