Reasonable　setting　of　tunnel　traffic　signs　can　alleviate　the“spatial-temporal　tunnel　effect”caused　by　the　special　environment　of　tunnels　to　a　certain　extent.　This　paper　studied　the　influence　of　traffic　signs　(speed　limit　signs　and　exit　warning　signs)　on　driving　behavior　in　highway　tunnels.　Firstly,　it　selected　long　tunnels　as　experimental　sections,　obtained　fine-grained　microscopic　behavioral　data　of　drivers　through　driving　simulator,　and　constructed　a　linear　mixed　effect　model　considering　the　influence　of　random　effects　to　reveal　the　influence　characteristics　and　mechanism　of　traffic　signs　on　driving　behavior　in　tunnels.　The　results　show　that:　there　are　differences　in　the　effects　of　traffic　signs　on　driving　behavior　in　different　influence　zones;　installation　of　speed　limit　signs　inside　the　tunnel　can　reduce　the　probability　of　accident　risk　to　a　certain　extent　and　the　repeated　setting　of　speed　limit　signs　can　improve　drivers’maneuvering　ability　to　a　certain　extent;　the　setting　of　speed　limit　signs　and　exit　distance　warning　signs　inside　the　tunnel　can　help　improve　drivers’spatial　control　ability　and　driving　comfort.　Among　them,　the　installation　of　tunnel　exit　distance　warning　signs　in　the　impact　zone　of　less　than　1km　from　the　tunnel　exit　helps　to　improve　the　driving　comfort　of　drivers;　the　installation　of　tunnel　exit　distance　warning　signs　in　the　impact　zone　of　2　km　and　1.　5　km　from　the　tunnel　exit　can　improve　the　vehicle　control　ability　and　at　the　same　time　make　drivers　have　a　higher　driving　speed.　In　addition,　driving　behavior　under　the　effect　of　tunnel　traffic　signs　is　influenced　by　driver’s　gender,　age,　driving　experience　and　other　characteristic　attributes,　with　male　drivers　having　a　lower　driving　risk.　©　2023　South　China　University　of　Technology.　All　rights　reserved.