Spinal cord injury (SCI) leads to motor, sensory and other functional disorders in patients, making it crucial to find effective methods for motor function recovery. As an emerging technology, functional electrical stimulation (FES) improves motor function by activating damaged neural pathways to promote muscle contraction. This paper reviews its research progress, including: in terms of mechanism, it uses low-frequency pulse current to activate α motor neurons to trigger muscle contraction, requiring the integrity of the lower motor neuron pathway; there are various technical types such as transcutaneous, implantable, wireless wearable ones, each with its own advantages and disadvantages; in application, it can restore grasping and other movements in the upper limbs and assist standing and walking in the lower limbs, but existing systems mostly rely on mechanical assistance, having portability and cost issues; current challenges include electrode performance, parameter optimization, muscle fatigue, etc.; future research hotspots focus on the combination with BCI, VR/AR, the development of new electrodes and intelligent systems to achieve more precise and efficient neural function reconstruction.