The　precipitation　of　dissolved　gas　in　oil　is　a　challenging　problem　in　pollution　control　of　hydraulic　systems.　When　the　self-excited　oscillation　jet　is　formed,　there　are　two　low-pressure　regions　in　the　self-excited　oscillation　cavity,　and　the　reduction　in　pressure　causes　the　dissolved　gas　in　the　oil　to　precipitate　out.　Here,　we　investigated　the　effect　of　the　self-excited　oscillation　cavity　on　the　dissolution　of　dissolved　gas　in　oil.　We　studied　the　gas　precipitation　performance　of　the　self-excited　oscillation　cavity　by　simulating　the　pressure　and　velocity　fields　inside　the　cavity　under　different　ratios　of　dimensionless　structure　parameters.　The　results　indicated　that　parameter　intervals　for　maintaining　good　gas　precipitation　performance　of　the　self-excited　oscillation　cavity　were　d2/d1=2-2.4,　D/d2=4-6,　and　D/L　=　2.　We　then　used　a　heuristic　prediction　algorithm　(Genetic　algorithm-backpropagation,　GA-BP)　to　fit　the　simulation　and　experimental　data,　in　which　the　root　mean　square　error　between　the　simulation　and　experimental　data　was　only　2.45%.　This　indicated　that　the　simulation　of　the　flow　field　was　reasonable,　and　that　the　GA-BP　model　performed　well　in　predicting　the　gas　precipitation　performance　of　the　self-excited　oscillation　cavity.　Our　results　have　important　guiding　significance　for　future　studies　on　the　gas　precipitation　performance　of　the　self-excited　oscillation　cavity.　©　2023　Author(s).