To　improve　fuel　economy　of　a　novel　series-parallel　hybrid　electric　bus　(SPHEB)　further,　the　control　rule　of　battery　power　distribution　is　derived　from　the　offline　optimisation　algorithm　based　on　Pontryagin＇s　minimum　principle,　internal　relationship　between　the　equivalence　fuel　factor　λ　and　trend　of　state　of　charge　(SOC)　with　different　driving　condition　is　established　and　calculation　model　of　SOC　is　formed.　On　the　basis　of　the　above,　according　to　the　feature　of　the　city　bus　driving　cycle,　the　algorithm　of　adaptive　fuzzy　sliding-mode　control　(AFSMC)　is　introduced　to　periodically　update　the　equivalence　fuel　factor,　and　then　the　power-balancing　adaptive　control　strategy　is　developed.　To　validate　the　proposed　strategy　rationality,　the　hardware　in-Theloop　integrated　with　bench　test　is　applied　to　compare　the　proposed　control　strategy　with　the　previous　optimal　control　strategy.　The　results　indicate　that　the　efficiency　of　SPHEB　system　is　improved　by　the　proposed　control　strategy.　©2016　Inderscience　Enterprises　Ltd.