The effect of inorganic fillers copper doped (Tb0.861Mn0.121)MnO3?δ on flexible magnetic thin films was investigated. Using Tb4O7, CuO and MnCO3 as raw materials, copper doped (Tb0.861Mn0.121)MnO3?δ was obtained by high temperature solid-state method. The copper doped (Tb0.861Mn0.121)MnO3?δ powder was fully dispersed in the polyvinyl alcohol solution according to different mass fractions. Then, the polyvinyl alcohol solution containing copper-doped (Tb0.861Mn0.121)MnO3?δ powder was prepared into magnetic films by wire rod on the treated iron plates. The hardness, adhesion, roughness, magnetism and flexibility of magnetic films were evaluated by pencil hardness test, drawing circle adhesion test, roughness test, low temperature physical properties test and flexibility test, and the phases were analyzed by XRD diffractometer and X-ray energy dispersive spectrometer. The addition of copper-doped (Tb0.861Mn0.121)MnO3?δ powder increases the rigidity and weakens the flexibility of the film, and the adhesion of the film remains unchanged. Compared with the resin film with zero addition, the tensile strength of the film with copper-doped (Tb0.861Mn0.121)MnO3?δ powder decreased. The transition temperatures from paramagnetic to antiferromagnetic of magnetic films with different mass fractions are almost the same, about 0.1 K.The addition of copper-doped (Tb0.861Mn0.121)MnO3?δ powder can maintain the magnetic properties of the film without reducing the adhesion of the coating. When less powder is added, the film has better flexibility.