A broadband metamaterial absorber based on a resonant structure made of conductive plastic film is proposed. The absorber adopts a three-layer structure model of dielectric layer-film unit array-dielectric layer, in which the upper dielectric layer performs the functions of impedance matching and protection of the resistive film resonant structure. Compared with the resistive film structure based on conductive ink, the conductive plastic film adopted not only overcomes the influence of uneven ink thickness on sheet resistance during processing,but also is compatible with the laser etching process, resulting in higher processing accuracy of the resonant structure. The simulation results show that the proposed absorber can maintain an incident wave absorptivity of more than 90% in the frequency range of 6.9-22.7 GHz, with a relative absorption bandwidth of 106.8%. In addition, the proposed structure is insensitive to the polarization characteristics of incident waves, and it can still achieve efficient absorption of electromagnetic waves with wide incident angles in a wide frequency band. More importantly, its resistive film resonant structure and dielectric substrate can be processed independently. Not only saving preparation time, but also removing the restriction of resistive film processing on the choice of substrate material, such a building block type of processing scheme provides a new approach for the development of broadband metamaterial absorbers.