Current differential protection is vitally important for transmission lines, but its performance is evidently impacted by the distributed capacitance, shunt reactance, static-var-compensators etc. For improvement, the active power based differential protection algorithms have been proposed by some scholars. But the active power differential algorithms exist dead-zone, because the voltage and active power is near zero when close metallic fault occurs. To cope with these shortcomings, the paper introduces a novel directional protection scheme based on fault components, and analyzes the performance from perspective of principle and simulation. The result of simulation shows that, when fault occurs, no matter inside or outside the protection zone, the proposed criterion possesses a higher resolution, and there is no dead-zone when close metallic fault occurs. In addition, the novel algorithm has the ability of tolerating asynchronous data and the advantage of lessen data exchange.