Compressed　air　energy　storage　(CAES)　has　attracted　substantial　attention　due　to　its　advantages,　including　low　cost,　long　lifespan,　and　low　environmental　pollution.　This　paper　establishes　a　test　bench　for　a　micro　CAES　system　based　on　a　scroll　expander　and　employs　experimental　methods　to　investigate　the　effects　of　key　parameters—regulated　pressure,　rotation　speed,　torque,　volume　flow　rate　(VFR),　and　expansion　ratio　on　the　output　performance　and　energy　conversion　efficiency　of　the　scroll　expander　and　generator.　The　experimental　results　indicate　that　the　power　output　of　the　scroll　expander　initially　increases　and　then　decreases　with　the　increase　of　torque,　rotation　speed,　expansion　ratio,　and　VFR.　The　compressed　air　consumption　rate　(CACR)　of　the　scroll　expander　initially　decreases,　stabilizes,　and　finally　slightly　increases　with　the　increase　of　torque　and　expansion　ratio.　The　CACR　of　the　scroll　expander　slightly　decreases　at　first,　then　flattens　out,　and　eventually　linearly　increases　trend　with　the　increase　of　rotation　speed　and　VFR.　The　power　output　of　the　generator　initially　increases　to　a　peak　value　and　then　declines　with　changes　in　torque,　rotation　speed,　expansion　ratio,　and　VFR.　The　energy　conversion　efficiency　of　the　generator　first　increases　to　the　maximum　value　and　then　decreases　with　the　increase　of　torque　and　rotation　speed.　To　achieve　high-efficiency　operation,　the　generator　should　operate　within　a　medium-to-low　torque　and　a　medium-to-high-speed　range,　with　a　maximum　efficiency　of　approximately　95　%.　©　2025　Elsevier　Ltd