The　crowding　and　jam　based　upon　the　urban　road　traffic　mainly　represent　in　the　fact　of　some　road-crossings.　The　Traffic　Guide　Simulation　System　Model　framework　in　which　the　four　road-crossings　are　taken　into　account　as　the　objects　will　be　brought　forward　in　the　paper.　Traffic　lights　are　used　for　controlling　the　phase　and　its　time　at　each　road-crossing　in　the　system.　Thereinto,　the　controlling　of　the　traffic　lights　at　the　road-crossing　is　provided　with　the　support　of　expert　system　who　simultaneity　considered　the　roadway　and　traffic　flow　in　four　road-crossings,　This　expert　system　not　only　use　for　reference　the　research　inside　and　outside　the　country　and　actual　production,　at　the　same　time,　it　is　also　stemmed　from　factual　experiences.