The invention discloses a method for live replacement of a lightning arrester by adopting a ground potential method and a special combined tool thereof. The method is characterized by consisting of a deformable sleeve and a lightning arrester handle, wherein the deformable sleeve comprises a lower insulating base (14), a 'U'-shaped cross arm clamping groove (2), an insulating operation rod clamping ring (3), a main insulating frame (1), a 'Pi'-shaped support (15), four bearings, two vertical gears, two horizontal gears, an operation rod sleeve connecting head (11) and a detachable sleeve (13). The lightning arrester handle comprises two mutually symmetrical insulating hand grabs (21) connected through a spring, hand grab clamping grooves (28), a top groove (29), a hand grab connecting mechanism (22), a long rotatable screw rod (25), a conical top head (26) and an operation rod hand grab connector (27). The method is simple in structure, convenient to install, safe, reliable and wide in application range, the hot-line working efficiency is improved, and the labor costs for enterprises are reduced.