Eight　drivers　were　selected　with　age　from　35　to　48,　Electrocardiograph,　Frecord　data　collecting　system　and　dynamics　GPS　are　utilized　to　study　the　drivers＇　behavior　under　emergency　in　the　Transportation　Communication　Trial　Field.　The　mix　effect　model,　which　is　affected　by　obstacle　distance,　driving　velocity,　driving　time,　personality,　is　established　to　study　the　inner　relationship.　The　predict　model　of　maximum　steering　velocity　based　on　heart　rate　is　obtained　and　obstacle　distance,　driving　velocity　have　obvious　effect　on　the　estimate　value　of　steering　velocity.　This　can　offer　new　method　for　the　drivers＇　behavior　analysis　under　emergency.