Traditional piezoelectric capturing systems have the disadvantages of narrow work bandwidths and fragile piezoelectric ceramic materials, which are unable to meet the requirements of wearable, miniaturized, or portable devices. This paper reports on high performance composite films based on BaTiO3/Graphene Oxide/polydimethyl siloxane (BaTiO3/GO/PDMS) with different GO content. GO with a large specific surface and strong fluidity was employed as a carbon-based conductive phase material to form micro-capacitors in the ferroelectric composite and thus enhance the piezoelectric performance of the given sample. The as-prepared BaTiO3/GO/PDMS composite films with 0.6 wt% GO showed a dielectric constant of 185 and a conductivity of 8.5×10-5 S/m. In addition, a remnant polarization of 13.47 μC/cm2 could be obtained, which is 28% higher than that of films of pure BaTiO3/PDMS. In contrast, the synthesized BaTiO3/GO/PDMS composite film exhibited a maximum output voltage of approximately 7.71 V, which is approximately 2.78 times higher than that of the film without GO. The performance of lead-free flexible piezoelectric nanogenerators was significantly enhanced after being compounded with GO materials. Moreover, an unsymmetrical interdigital harvester with BaTiO3/GO/PDMS piezoelectric materials was fabricated. The results indicated that the output voltage of the harvester compounded with GO increased and that the -3 dB bandwidth of harvesters increased from 8.7 Hz (without GO) to 11.2 Hz (with GO). Therefore, the proposed BaTiO3/GO/PDMS lead-free flexible composite piezoelectric nanogenerator presents great prospects in flexible energy harvesting.