In　order　to　overcome　the　limitations　of　geological　conditions,　a　test　bench　of　small-scale　compressed　air　energy　storage　(CAES)　system　based　on　pneumatic　motor　(PM)　is　proposed　in　this　paper.　As　a　key　component　of　CAES　system,　the　PM　serves　as　an　expander　with　the　advantages　of　small　size,　lightweight,　low　cost,　and　convenient　operation.　The　effect　of　the　rotation　speed,　regulated　pressure,　and　current　on　the　key　performance　parameters　(power　output,　compressed　air　consumption　rate,　and　energy　efficiency)　are　tested　through　experiments.　In　addition　to　the　resulting　output　performance　of　the　PM　and　generator,　the　energy　efficiency　of　the　PM,　generator,　and　CAES　system　is　analyzed.　Given　that　the　exhaust　air　from　the　PM　has　a　refrigeration　potential,　the　cooling　power,　cooling　efficiency,　and　combined　cooling　power　efficiency　are　also　examined　to　improve　the　comprehensive　energy　utilization　efficiency　of　the　CAES　system.　The　power　output　and　energy　efficiency　of　the　PM　and　generator　increase　but　eventually　decrease　with　the　rise　of　current　and　rotation　speed.　Under　the　lab-scale　conditions,　the　maximum　power　output　of　the　PM　and　generator　are　989.21　W　and　862.35　W,　respectively.　The　maximum　efficiency　of　the　PM　and　generator　is　9.83%　and　87.19%,　and　the　cooling　efficiency　and　combined　cooling　power　efficiency　of　the　CAES　system　are　11.77%　and　17.25%.