Compressed-air　energy　storage　has　been　considered　as　a　promising　technology　to　smooth　the　fluctuations　of　renewable　energy　sources　and　improve　the　peak-shaving　flexibility　capacity　of　power　systems.　In　order　to　improve　the　energy　degree　of　compression　heat　and　enhance　the　system　performance,　the　current　paper　described　a　novel　combined　heating　and　power　system　that　integrates　compressed-air　energy　storage　with　thermochemical　technology.　In　the　proposed　system,　the　compression　heat　is　coupled　with　methanol　decomposition　reaction　to　convert　the　thermal　energy　to　chemical　energy　(H2　and　CO).　A　sensitivity　analysis　was　carried　out　to　investigate　the　effects　of　five　key　parameters　on　the　system　performance.　The　results　indicated　that　higher　values　of　air-to-methanol　ratio,　pressure　ratio,　and　isentropic　efficiency　of　gas　turbine　have　positive　influences　on　the　thermodynamic　performance　of　the　proposed　system.　In　addition,　the　multiobjective　optimization　was　implemented　to　ascertain　the　optimum　performance　from　the　aspect　of　thermodynamics　and　economics.　The　optimal　condition　selected　using　the　technique　for　order　preference　by　similarity　to　an　ideal　solution　(TOPSIS)　method　demonstrated　that　the　exergy　efficiency　and　levelized　cost　of　energy　of　the　proposed　system　are　39.42%　and　$96.58/MWh,　respectively.　©　2022　American　Society　of　Civil　Engineers.