This study presents an innovative dual-mode electromagnetic-triboelectric-piezoelectric multifunctional self-charging energy system (MS-CES) that integrates two different operating modes of electromagnetic generators for contact-separation (CS-EMG) and non-contact (NC-EMG), as well as a triboelectric nanogenerator (TENG) and a piezoelectric nanogenerator (PENG). The system has an energy management circuit that efficiently captures and converts kinetic energy from the environment. We investigate the output performance of each unit of the MS-CES under different vibration frequencies and amplitudes. The units work together through a compact mechanical structure design to achieve high voltage output while shortening charging time based on improved space utilization, thus gaining more efficient energy storage. Polyacrylonitrile (PAN) powder and barium titanate (BTO) composite nanofibre membrane (PAN/BTO) as PENG material further enhances the system's output performance. The system provides a continuous power source for the vibration sensors. It enables human-computer interaction with mobile phones and computers via Bluetooth modules, enabling real-time monitoring and analysis of vibration parameters. Furthermore, we have validated the feasibility of using the MS-CES to power a noninvasive vagus nerve stimulation device, providing new technological means for monitoring and treatment in the medical field.