As　the　power　of　the　automotive　fuel　cell　increases,　the　traditional　orbiting-type　scroll　compressor　may　not　meet　fuel　cell　cathode　inlet　air　mass　flow　demand.　To　improve　the　air　compressor　discharge　mass　flow,　the　optimal　structure　and　performance　of　a　novel　variable　cross-section　double-scroll　compressor　with　co-rotating　have　been　investigated.　The　effects　of　different　structural　parameters　on　the　performance　are　analyzed　by　sensitivity　analysis　method.　A　multi-objective　grey　wolf　optimization　algorithm　is　applied　to　optimize　the　structural　parameters　of　the　scroll　compressor.　After　that,　the　heat　characteristics　of　the　co-rotating　air　compressor　initial　and　optimized　designs　are　analyzed　and　verified　by　computational　fluid　dynamics　method.　The　results　exhibit　that　the　optimized　design　structure　could　increase　the　mass　flow　rate　and　pressure　ratio　by　4.49　%　and　10.53　%,　respectively,　while　reducing　the　area　utilization　coefficient　and　total　scroll　teeth　mass　by　6.41　%　and　10.77　%,　respectively,　compared　to　the　initial　design.　The　compressor　could　achieve　optimal　performance　when　the　discharge　pressure　approaches　the　design　pressure,　with　the　maximum　isentropic　efficiency　reaching　88.20　%.　As　the　rotational　speed　and　radial　clearance　improve,　both　the　gas　leakage　rate　and　the　discharge　temperature　of　the　scroll　compressor　increase.　When　the　radial　clearance　is　0.075　mm,　the　leakage　velocity　is　21.33　%　higher　compared　to　a　radial　clearance　of　0.030　mm.　The　research　findings　provide　valuable　insights　for　designing　high-performance　co-rotating　scroll　compressors,　offering　an　efficient,　compact,　and　reliable　gas　supply　solution　for　high-power　fuel　cell　systems.　©　2025　Elsevier　Ltd