Soft　robots,　inspired　by　living　organisms　in　nature,　are　primarily　made　of　soft　materials,　and　can　be　used　to　perform　delicate　tasks　due　to　their　high　flexibility,　such　as　grasping　and　locomotion.　However,　it　is　a　challenge　to　efficiently　manufacture　soft　robots　with　complex　functions.　In　recent　years,　3D　printing　technology　has　greatly　improved　the　efficiency　and　flexibility　of　manufacturing　soft　robots.　Unlike　traditional　subtractive　manufacturing　technologies,　3D　printing,　as　an　additive　manufacturing　method,　can　directly　produce　parts　of　high　quality　and　complex　geometry　for　soft　robots　without　manual　errors　or　costly　post-processing.　In　this　review,　we　investigate　the　basic　concepts　and　working　principles　of　current　3D　printing　technologies,　including　stereolithography,　selective　laser　sintering,　material　extrusion,　and　material　jetting.　The　advantages　and　disadvantages　of　fabricating　soft　robots　are　discussed.　Various　3D　printing　materials　for　soft　robots　are　introduced,　including　elastomers,　shape　memory　polymers,　hydrogels,　composites,　and　other　materials.　Their　functions　and　limitations　in　soft　robots　are　illustrated.　The　existing　3D-printed　soft　robots,　including　soft　grippers,　soft　locomotion　robots,　and　wearable　soft　robots,　are　demonstrated.　Their　application　in　industrial,　manufacturing,　service,　and　assistive　medical　fields　is　discussed.　We　summarize　the　challenges　of　3D　printing　at　the　technical　level,　material　level,　and　application　level.　The　prospects　of　3D　printing　technology　in　the　field　of　soft　robots　are　explored.