Multi-axle　heavy　vehicles　employ　a　variable-length　tie　rod　steering　system　to　achieve　precise　multi-mode　steering.　However,　the　single-axle　steering　system　need　integrate　two　sets　of　electro-hydraulic　control　systems　(EHCSs),　resulting　in　the　energy　consumption　significant　increase.　This　paper　proposes　a　novel　energy-efficient　pump-valve　primary-auxiliary　electro-hydraulic　steering　system　(PVPA　EHSS)　which　compose　of　a　pumpcontrolled　dual-steering　cylinders　primary　system　and　a　valve-controlled　variable-length　tie　rod　cylinder　auxiliary　system.　The　proposed　system　utilizes　a　single　pump　to　drive　both　the　primary　and　auxiliary　EHCSs　simultaneously,　enabling　high-precision　and　high-efficiency　steering　with　multi　steering　modes.　Additionally,　to　suppress　the　flow　disturbance　of　the　auxiliary　system　branch　flow　on　the　single-pump-controlled　steering　primary　system,　the　interaction　between　the　flow　of　the　auxiliary　system　and　the　flow　of　the　primary　system　in　each　steering　phase　is　studied.　A　pump　flow　feedforward-angle　feedback　composite　control　strategy　incorporating　branch　flow　prediction　is　proposed　to　mitigate　the　disturbance　and　ensure　the　accurate　steering　of　left　and　right　tires.　The　experimental　results　demonstrate　that　compared　to　the　traditional　variable-length　tie　rod　steering　system,　the　proposed　system　reduces　energy　consumption　by　58.66　%,　and　achieves　precise　adaptation　of　the　left　and　right　tire　angles　in　multi　steering　modes.