To　deal　with　the　mismatched　uncertainty　and　state　time-delay　perturbations　in　vehicle　lane-keeping　control,　we　propose　a　self-turning　sliding　mode　control　method.　By　using　the　linear　matrix　inequality　theory,　we　develop　the　sufficient　conditions　for　the　existence　of　the　sliding-mode,　in　which　the　system　in　the　sliding　phase　is　completely　independent　to　the　existing　mismatched　uncertainties　and　the　state　time-delay.　The　sigmoid　function　is　adopted　to　replace　the　sign　function　in　designing　the　self-tuning　law,　by　which　the　boundary　layer　of　the　sigmoid　function　as　well　as　the　switching　gain　can　be　adjusted　automatically　to　reduce　the　high　frequency　chattering　in　outputs.　The　stability　of　the　control　method　is　proved　based　on　Lyapunov　theorem.　Simulation　results　show　the　correctness　and　feasibility　of　the　proposed　method.