As a kind of mature non-invasive brain stimulation technology, transcranial direct current stimulation (tDCS) has shown significance in clinic. Recently, DCS has been applied over the scalp to the spinal cord, named transcutaneous spinal direct current stimulation (tsDCS), that may modulate the spinal cord tracts and spinal cord loop electrical activity at segmental level, and may benefit in the treatment of chronic pain and motor dysfunction after injury of nervous system. This paper reviewed physiological effects, safety considerations and potential clinical applications of tsDCS.