The characteristics of grid-forming (GFM) inverter faults make the traditional transmission line pilot protection a great challenge, and there is a risk of refusal or false activation. This paper proposes a new type of pilot protection method for grid-forming new energy transmission lines, which quantitatively portrays the difference between the current waveforms of the two ends of the line through the dynamic pattern matching distance, and realizes reliable identification of line faults by constructing the protection setting value according to the dynamic pattern matching distance. The simulation results of PSCAD show that the proposed method can reliably and sensitively identify various types of short-circuit faults, and it has a strong resistance to transition resistances and anti-interference ability.