Pre-warning　experimental　system　of　driving　fatigue　has　become　a　hotspot　and　difficulty　of　auto　safety.　Based　on　existing　study　and　experimental　equipment,　the　pre-warning　experimental　system　of　driving　fatigue　at　the　view　of　formation　mechanism　of　driving　fatigue　was　introduced　in　the　paper.　The　system　included　data　collection　module,　fatigue　detection　module,　countermeasure　generation　module　and　countermeasure　effectiveness　validation　module.　The　function　of　the　system　is　to　provide　experiment　platform　for　validating　effectiveness　of　countermeasure　against　driving　fatigue,　to　provide　scientific　and　safe　pre-warning　signals　for　pre-warning　system　of　driving　fatigue.　Firstly,　the　system　detected　and　judge　drivers＇　fatigue　state,　once　detected　drivers　fatigue,　then　the　system　gave　pre-warning　signals　from　sight,　hearing,　feeling,　etc;　Secondly,　orthogonal　experiment　was　used　to　design　experiment　program　and　study　the　effectiveness　of　various　external　stimulus　to　reduce　driving　fatigue;　Finally,　the　effective　pre-warning　signals　against　driving　fatigue　was　proposed.　It　will　provide　theoretical　basis　for　effective　and　safe　pre-warning　system　of　driving　fatigue.　The　paper　took　the　effectiveness　of　sound　stimulus　for　example,　introduced　the　method　how　to　evaluate　the　effectiveness　of　pre-warning　signals　used　the　experiment　system.