In　order　to　achieve　safe　and　comfortable　threshold　zone　light　environment　of　tunnels,　from　the　point　of　the　driver＇s　visual　function　and　requirement,　a　threshold　zone　light　environment　evaluation　method　was　proprosed　based　on　the　driving　safety　of　visual　cognition.　Taking　the　color　temperature　of　5　700　K,　and　the　color　rendering　index　of　70　threshold　zone　light　environment　as　the　research　object,　car　drivers　were　chosen　for　visual　cognition　testing　with　different　running　speed,　to　get　the　drivers＇　dynamic　visual　characteristics.　The　visual　cognition　distance　was　selected　as　the　evaluation　index　of　tunnel　threshold　zone　safety　visual　cognition.　The　Matlab　mathematical　statistics　software　was　applied　to　establish　the　logistic　regression　model　of　visual　cognition　distance　and　luminance　reduction　coefficient.　Different　design　speed　luminance　reduction　coefficients　which　could　meet　the　demand　of　driving　visual　cognition,　and　slightly　higher　than　the　current　specification　values　were　obtained.　The　research　method　and　conclusions　is　this　paper　can　provide　technical　reference　for　actual　tunnel　environment　setting,　monitoring　and　operation　management.　©,　2015,　Shanghai　Jiao　Tong　University.　All　right　reserved.