The　effectiveness　of　interchange　diagrammatic　guide　signs　has　significant　meaning　in　traffic　safety　and　driver＇s　understanding.　This　paper　presented　a　comprehensive　evaluation　and　classification　of　interchange　diagrammatic　guide　signs＇　complexity.　The　effectiveness　of　interchange　diagrammatic　guide　signs　relies　on　how　well　road　users　can　understand　those　diagrams.　This　study　tested　37　types　of　diagrams　on　the　visual　recognition　complexity　degree　in　three　levels,　general　level,　partial　level,　and　detailed　level,　and　finally　seven　indexes　are　selected　to　evaluation　and　classification　of　interchange　diagrammatic　guide　signs＇　complexity.　These　indexes　can　be　used　to　conduct　quantitative　evaluation　and　classification.　And　the　result　of　diagram　complexity　range　is　between　-1.366　and　2.046,　which　have　a　correlation　with　graph　cognition　complexity,　including　perspective　of　distribution,　diagram　character,　essential　element　expression　manner,　and　utilization　degree,　and　K-means　clustering　method　was　used　in　the　analysis.　Based　on　the　presented　method,　37　types　of　diagrams　are　separated　into　three　categories　according　to　their　complexity　score:　low　complexity,　medium　complexity,　and　high　complexity.　This　study　not　only　presents　a　theoretical　approach　for　quantitative　evaluation　of　guide　signs＇　complexity　and　effectiveness　but　also　can　be　a　reference　for　traffic　sign　design　and　application.