With　the　large-scale　use　of　intermittent　renewable　energy　worldwide,　energy　storage　systems　are　important　for　dealing　with　the　fluctuation　of　renewable　energies.　In　this　paper,　a　novel　near-　isothermal　pumped　hydro　compressed　air　energy　storage　system　without　thermal　energy　storage　is　proposed;　The　exhausted　salt　cavern　of　double　well　is　employed　as　the　air　storage　vessel　in　this　proposed　system.　To　detect　the　thermodynamic　and　economic　of　this　system,　the　detailed　thermodynamic　and　economic　model　of　both　the　main　components　and　the　whole　system　have　been　built.　The　results　showed　that　the　electrical　efficiency　of　the　system　can　reach　61.6%,　and　the　exergy　efficiency　can　achieve　72.3%.　Moreover,　the　economic　performance　of　the　system　shows　that　the　cost　of　cavern　is　more　than　60%　of　the　total　energy　storage　system.　The　payback　period　of　the　proposed　system　decreases　with　the　increase　of　output　power　of　energy　storage　system.　By　numerical　calculation,　when　the　energy　storage　scale　of　the　system　is　4MW,　the　payback　period　of　the　system　is　reduced　to　6.15　years.　©　2020　Elsevier　Ltd