The utility model discloses a tandem type line protector, which comprises a shell with an open inner cavity structure, a protective cover is arranged on the shell, two positioning grooves are arranged in the shell, limit nuts are respectively arranged in the two positioning grooves, fastening screws are matched with the limit nuts, and a fuse is arranged between the two limit nuts. One end of the fusing fuse is connected to the limiting nut, the other end of the fusing fuse is connected to the limiting nut, the limiting nut is connected with positioning terminals through fastening screws, the fusing fuse is connected to a wire in series through the two positioning terminals, one side of the safety cover is hinged to the shell, and the other side of the safety cover is connected with the shell through a buckle. The line protector provided by the utility model is an external independent protection unit, the hot melting fuse is transferred from the inside of the plug to the inside of the special protection shell, and spring clip connection is replaced by thread mechanical locking, so that the risk of loosening of a contact surface is eliminated, meanwhile, the heat dissipation surface area can be enlarged, and heat accumulation is avoided.