The invention belongs to the low-current grounding fault technical field and relates to a transient power direction-based hand-in-hand line low-current grounding fault processing method. According tothe transient power direction-based hand-in-hand line low-current grounding fault processing method of the invention, a transient power direction and delay combined method is adopted to process the low-current grounding fault of a hand-in-hand line; a fault section can be judged on the basis of transient power directions; and action delay is set for switches; and corresponding switches at the upstream or downstream of the fault section are controlled to trip after set delay time comes. The method does not rely on communication, and does not affect the normal power supply of a valid section atthe upstream of a fault point; and a risk that a valid section line undergoes secondary power failure can be avoided, and fault processing efficiency can be improved.