The　high　demand　for　flexible　spintronics　based　on　multiferroic　heterostructures　makes　growing　high-quality　flexible,　functional　oxides　urgently,　in　which　needs　to　be　deposited　on　lattice-matched　substrates.　In　this　paper,　ultraflexible　and　malleable　iron　(Fe)/BaTiO3　(BTO)　multiferroic　heterostructures　are　demonstrated,　showing　a　perfect　crystallinity　and　hetero-epitaxial　growth.　In　terms　of　performance,　they　indicate　good　multiferroic　properties　and　excellent　bending　tunability,　as　well　as　obvious　magnetoelectric　(ME)　coupling　effect.　During　the　phase　transformation　from　the　rhombohedral　phase　to　the　orthorhombic　phase　of　BTO　layers　in　the　heating　process,　a　large　ME　coupling　coefficient　of　120　Oe　degrees　C-1　along　the　out-of-plane　direction　is　obtained.　This　value　keeps　consistent　in　the　phase-field　simulation　of　magnetic　domain　evolution,　in　which　the　biaxial　compressive　strain　induced-magnetoelastic　anisotropy　facilitates　the　magnetic　easy　axis　of　Fe　layers　to　the　[110]　or　[-1-10]　direction.　Besides,　ultraflexible　Fe/BTO　heterostructures　are　found　to　have　a　690　Oe　ferromagnetic　resonance　(FMR)　field　shift　along　the　out-of-plane　direction　under　the　flexible　tuning　(R　=　5　mm).　This　work　should　pave　a　way　toward　flexible　spintronic　and　functional　devices　with　fast　speed,　portability,　and　low　energy　consumption.