The　variable　background　harmonic　data　and　incomplete　phasor　information　make　multi-harmonic　source　responsibility　division　in　three-phase　symmetrical　power　system　a　significant　challenge.　In　this　paper,　a　background　harmonic　data　selection　method　based　on　canonical　correlation　analysis　is　proposed　to　deal　with　multi-harmonic　source　responsibility　division　without　phasor　information.　Firstly,　the　canonical　correlation　coefficient　between　harmonic　voltage　and　harmonic　current　is　used　to　characterize　the　fluctuations　of　background　harmonic　voltage.　Then,　the　sliding　window　method　is　adopted　to　select　the　harmonic　voltage　and　harmonic　current　with　small　fluctuations.　Next,　the　canonical　correlation　results　for　selected　data　are　used　to　calculate　the　harmonic　responsibility　index　via　the　linear　regression　method.　The　harmonic　responsibility　index　in　the　form　of　percentage　represents　the　harmonic　responsibility　division.　Finally,　several　experimental　results　demonstrate　that　the　proposed　method　has　a　high　accuracy　in　calculating　the　harmonic　responsibility　division,　particularly　when　the　user　side　contains　fluctuations　of　unknown　harmonic　sources.