An　interval　power-flow　equation　based　on　the　complex　affine　Ybus-Gaussian　iteration　is　established,　which　applies　the　complex　affine　to　describe　the　uncertainties　of　DG　outputs　and　state　variables.　With　the　consideration　of　both　efficiency　and　accuracy　of　interval　power-flow　calculation,　similar　noise　elements　are　merged　to　suppress　the　noise　element　increase　during　the　iteration.　The　complex　affine　is　adopted　to　calculate　the　intervals　of　voltage　amplitude　and　phase-angle.　IEEE　33-bus　system　is　applied　to　verify　the　effectiveness　and　correctness　of　the　proposed　method.　©　2017,　Electric　Power　Automation　Equipment　Press.　All　right　reserved.