The invention discloses a detonator tail line connecting device and method. The connecting device comprises a connecting plug, a connecting receptacle and a female bushing, wherein the female bushingis nested on a tail line and can rotate relative to the tail line; a first tool bit connected with a detonator control chip is arranged on the connecting plug, and a tail line connecting line with aninsulating layer is arranged on the connecting receptacle; the female bushing comprises a connecting threaded section, a truncated cone-shaped transition section and a pressing section sequentially. The detonator is transported separately from an outer line, the connecting plug of the detonator and the connecting receptacle of the tail line end are connected through a female thread during assembly, the matching part of the connecting plug and the connecting receptacle is extruded by the transition section of the female bushing, so that the tool bit cuts the insulating layer of the tail line, and the detonator and the tail line are connected. Accordingly, transportation safety can be improved, transportation cost can be reduced, and on-site assembly of the detonator and the tail line is simple and rapid to operate and high in reliability.