The embodiment of the invention discloses a line and transformer set protection method and device, which is used for being compatible with outage protection on a transformer and a power transmission line under different conditions and improving practicability of line and transformer set protection. The method disclosed by the embodiment of the invention comprises the steps that when a fault occursin the transformer, an action switch connection point of a transformer protection device is closed, and an action opening connection point of the transformer protection device is connected with a closing connection point of a shunting reclosing brake in a line protection screen; the reclosing brake is shunted so that the transformer and the power transmission line are maintained in a power-failure state; when an instantaneous fault occurs in the power transmission line, the action switch connection point of the transformer protection device is broken, and the action opening connection point of the transformer protection device is disconnected with the closing connection point of the shunting reclosing brake; and the reclosing brake is reclosed so that the transformer and the power transmission line are restored to a connection state.