Compressed　air　energy　storage　is　a　promising　technology　with　the　advantages　of　zero　pollution,　long　lifetime,　low　maintenance,　and　minimal　environmental　impact.　However,　compressed　air　energy　storage　has　some　disadvantages,　such　as　low　efficiency　and　low　energy　density.　A　parallel　operation　mode　of　pneumatic　motor　is　proposed　in　this　study　to　improve　the　power　performance,　energy　conversion　efficiency,　and　economy　of　compressed　air　energy　storage　system.　First,　the　test　bench　of　compressed　air　energy　storage　system　is　established.　Then,　the　influence　of　key　parameters,　such　as　current,　rotating　speed,　and　regulated　pressure,　on　the　output　performance　of　compressed　air　energy　storage　system　is　investigated　in　this　study.　Afterward,　the　interaction　among　volume　flow　rate,　rotating　speed,　torque,　output　power　of　pneumatic　motor,　and　the　current,　voltage,　and　output　power　of　the　generator,　as　well　their　influence　on　one　another,　are　discussed.　Finally,　the　output　performances　of　compressed　air　energy　storage　system　when　the　pneumatic　motor　works　alone　and　in　parallel　are　compared　and　analyzed.　The　experimental　results　show　that　the　power　performance,　energy　conversion　efficiency,　and　economy　of　compressed　air　energy　storage　system　can　be　improved　when　the　pneumatic　motor　works　in　parallel　operation　mode.　The　minimum　compressed　air　consumption　rate　is　0.1369　g/J,　the　maximum　power　output　is　818　W,　the　maximum　efficiency　of　the　generator　is　88.7%,　and　the　maximum　efficiency　of　pneumatic　motor　is　6.5%　when　the　pneumatic　motor　works　in　parallel　operation　mode.