In　order　to　improve　the　cooling　and　dehumidification　performance　of　household　air　conditioners,　a　new　air　conditioning　system　with　double　evaporation　temperature　is　proposed.　The　simulation　model　of　the　new　system　is　established,　the　variation　of　system　performance　with　compressor　high/low　pressure　cylinder　volume　ratio,　inlet　air　temperature,　relative　humidity,　air　speed,　etc.　are　simulated　and　experimentally　studied.　The　research　results　show　that　when　the　volume　ratio　of　high　and　low　pressure　cylinders　of　compressor　is　0.5　similar　to　1.2　and　air　speed　2.2　m/s,　cooling　COP　of　double　evaporation　temperature　air　conditioning　system　could　obtain　the　maximum　value.　Compared　with　single　evaporation　temperature　system,　cooling　COP　of　double　evaporation　temperature　system　can　be　increased　3%similar　to　4.2%;　the　dehumidification　capacity　is　0.06　similar　to　0.61　kg/h,　about　1.69%　similar　to　5.83%　higher.