AimingatthegeometricalfeaturesofdifferentcontainmentrelationshipsinRapidPrototyping(RP),ageneralmethodofachievingtheRPlayer’scuspdistributionofthepositive,negativeandmixedtoleranceisproposedtomeetthepart’sdifferentapplications.TheprocedureisexecutedbyprojectingthecurrentandthenextsectionoftheCADmodelontoahorizontalplane,computingtheunionandtheintersectionofthesectionstogettheouterandtheinnerboundary,andthenblendingtheboundariesusingarotaryvectorthroughaproperinnerpointintheintersectiontoachievethecurrentlayer’sscanningcontour.Themethodcanrealizethelayer’scuspdistributionofthemixedtolerancewithunequalcuspheight,expandingtheconnotationofthemixedtolerance.