Aiming　at　the　problem　of　uncertainty　and　state　time　delay　disturbances　in　vehicle　lane　keeping　control,　a　self-tuning　sliding　mode　control　method　is　proposed.　With　the　method　firstly　the　sufficient　condition　for　the　existence　of　integral　sliding　surface　is　given　by　applying　linear　matrix　inequality　theory,　so　that　the　system　has　complete　invariance　to　uncertainty　and　state　time　delay　disturbances　under　sliding　mode.　Then　bipolar　Sigmoid　function　is　introduced　to　replace　signum　function　and　a　sliding　mode　controller　with　self-tuning　capability　is　designed　based　on　Lyapunov　stability　theory　so　that　the　switching　gain　and　the　boundary　layer　thickness　of　Sigmoid　function　can　be　adaptively　adjusted　to　mitigate　the　phenomena　of　the　excessive　quantity　and　chattering　of　sliding　mode　controller　output.　Finally,　the　simulation　results　of　vehicle　lane　keeping　control　on　curved　road　verify　the　feasibility　and　effectiveness　of　the　control　method.