This review summarizes recent advances in femtosecond laser direct writing for flexible electronic devices. Femtosecond lasers offer high precision, flexibility, and compatibility with various materials, enabling the fabrication of micro/nanostructures in flexible electronics. The review discusses the physical mechanisms of femtosecond laser processing, including electron excitation, energy transfer, and phase transitions. It highlights the advantages of femtosecond lasers over longer pulses, such as cold processing, versatility in material treatment, and high-resolution processing. The review also covers practical processing technologies, including direct writing, spatial-temporal pulse shaping, and laser sintering, which enhance processing efficiency and accuracy. Applications of femtosecond laser processing in flexible electronics include energy storage devices, triboelectric nanogenerators, sensors, and detectors. The review discusses the challenges and future prospects of femtosecond laser processing in flexible electronics, emphasizing the need for further research to optimize processes and improve device performance. The review concludes that femtosecond laser technology is a promising tool for the precise manufacturing of flexible electronic devices.This review summarizes recent advances in femtosecond laser direct writing for flexible electronic devices. Femtosecond lasers offer high precision, flexibility, and compatibility with various materials, enabling the fabrication of micro/nanostructures in flexible electronics. The review discusses the physical mechanisms of femtosecond laser processing, including electron excitation, energy transfer, and phase transitions. It highlights the advantages of femtosecond lasers over longer pulses, such as cold processing, versatility in material treatment, and high-resolution processing. The review also covers practical processing technologies, including direct writing, spatial-temporal pulse shaping, and laser sintering, which enhance processing efficiency and accuracy. Applications of femtosecond laser processing in flexible electronics include energy storage devices, triboelectric nanogenerators, sensors, and detectors. The review discusses the challenges and future prospects of femtosecond laser processing in flexible electronics, emphasizing the need for further research to optimize processes and improve device performance. The review concludes that femtosecond laser technology is a promising tool for the precise manufacturing of flexible electronic devices.