With the development of technology, self-powering devices by harvesting bioenergy is an efficient way to achieve sustainable system operation. In this paper, we fabricated a flexible hybrid nanogenerator (HNG) based on multilayer nanocomposites, innovatively using biocompatible Polylactic acid (PLA) as piezoelectric material and multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) as triboelectric material. A simple method was used to prepare the MWCNTs/PDMS films with surface microstructure. By coupling the triboelectric effect and the piezoelectric effect, a 3 cm × 3 cm HNG can generate an output of 80 V and 125 nA under a pressure stimulation of 20 N. Furthermore, due to the good flexibility and biocompatibility of our device, we can use it to harvest human energy.