3D　printing　technology　is　a　rapid　prototyping　technology　which　is　in　the　process　of　fast　development.　It　has　the　advantages　of　no　mold　requirement,　high　precision　and　high　shape　controllability.　To　apply　3D　printing　in　the　field　of　electric　engineering,　it　is　necessary　to　understand　the　insulating　properties　and　the　microstructure　of　the　printing　parts.　In　this　paper,　several　commonly　used　3D　printing　techniques　are　taken　into　consideration,　including　stereolithography　apparatus　(SLA),　fused　deposition　modeling　(FDM),　and　selective　laser　sintering　(SLS).　Representative　materials　for　these　3D　printing　process　are　selected,　i.e.　High　Temp　resin　for　SLA,　PLA　and　ABS　for　FDM　and　PA2200　for　SLS.　The　surface　and　interior　morphology　of　the　3D　printing　parts　were　characterized,　then　the　dielectric　parameters　and　electrical　withstanding　ability　of　the　four　materials　were　tested.　Finally,　a　comprehensive　evaluation　was　made　on　whether　the　3D　printing　techniques　were　suitable　for　electrical　insulation.　The　test　results　showed　that,　SLA　process　parts　have　the　best　morphology　feature,　and　there　are　defects　in　FDM　and　SLS　process　parts.　The　dielectric　parameters　of　the　four　materials　meet　the　requirements　as　insulating　materials,　and　the　breakdown　strength　are　all　above　30　kV/mm.　It　can　be　said　that　the　development　of　3D　printing　technology　in　the　field　of　electrical　engineering　has　high　feasibility,　and　different　processes　and　materials　have　their　own　suitable　applications.