A　broad-speed-range　operational　capability　coupled　with　both　subsonic　and　supersonic　flight　performances　is　a　key　factor　for　new　aircraft　design.　The　joined-wing　configuration　has　higher　bending　torsional　strength,　lower　induced　resistance,　larger　lift　coefficient,　and　better　stability　in　comparison　to　traditional　wing　configuration.　A　new　morphing　joined-wing　aircraft　that　featured　a　retractable　wing　installed　in　the　front　wing　was　designed　in　the　present　work　to　satisfy　the　transition　between　the　joined-wing　and　box-wing　configurations,　thereby　attaining　transonic　flight　capability　across　a　wide　range　of　speeds.　The　simulation　models　of　the　joined-wing　and　box-wing　configurations　were　built　based　on　the　JW-1　model,　and　the　flight　characteristics　of　the　aircraft　under　different　flow　field　speeds　were　studied　based　on　the　Spalart-Allmaras　turbulence　model.　The　effects　of　different　parameters　on　the　morphing　aircraft　under　subsonic　and　supersonic　conditions　were　analyzed,　and　the　flight　performance　of　the　morphing　joined-wing　aircraft　was　compared　with　those　of　conventional　aircraft　wing　configurations.　This　study　provides　valuable　insights　into　the　optimization　of　supersonic　flight　for　the　joinedwing　aircraft.