The　evaluation　of　the　efficiency　and　feasibility　of　energy　transition　and　air　pollution　control　at　the　city　level　is　one　of　the　key　points　in　addressing　environmental　problems　and　achieving　the　goals　of　CO2　emission　reduction　and　carbon　neutrality　in　China.　In　this　study,　an　integrated　method　is　developed　on　the　basis　of　the　Low　Emissions　Analysis　Platform　(LEAP)　and　life　cycle　assessment　(LCA).　The　energy　demands　and　environmental　co-benefits　in　Jinan,　one　of　the　low-carbon　city　pilots　in　China,　are　quantitatively　evaluated　under　three　policy　scenarios:　low-carbon　(LC)　policy　scenario,　pollution　control　(PC)　policy　scenario,　and　deep-level　cut　of　CO2　emissions　(DCC)　scenario　from　2016　to　2050.　From　2016　to　2030,　the　PC　policies　would　be　more　powerful　than　the　LC　policies　in　terms　of　energy　demand　decrease.　From　2030　to　2050,　the　LC　policies　would　be　more　efficient　than　all　the　other　policies.　Promoting　energy-saving　buildings　in　the　LC　scenario　would　contribute　to　the　continual　decline　in　energy　demands.　In　the　DCC　scenario,　CO2,　PM2.5,　PM10,　CO,　NOX　and　SO2　emissions　would　decline　by　more　than　71.4%　relative　to　the　records　in　2016.　Global　warming　potential,　human　toxicity　potential,　photochemical　ozone　creation　potential,　particulate　matter　formation　potential,　and　acidification　potential　would　also　decrease　by　81.8%-88.5%.　On　the　basis　of　the　integrated　city-level　LEAP　and　LCA　method,　this　study　quantifies　the　various　environmental　impacts　of　urban　decarbonization　policies　and　provides　science-based　references　for　urban　low-carbon　transformation.