Abstract: With the prosperous development of the new power system, power frequency protection may not act correctly. This makes transient-based protection, which is not affected by the characteristics of new energy, regain public attention. In this respect, given the advantages of the non-unit transient-based boundary protection for full-line quick operation, little research has been done on whether a new transient-based boundary protection can be designed based on the existing boundary elements of the high-voltage system. Therefore, this paper finds that the capacitive voltage transformer, the metal-oxide arrester, and the busbar stray capacitance can be used together as the line boundary of the 220 kV high-voltage system, which has strong high-frequency filtering characteristics and lays a foundation for the design of the boundary protection. Then, based on the Teager energy operator, a new protection criterion is constructed due to the difference in the instantaneous energy ratio of high- to low-frequency band of the internal and external fault current traveling waves. Furthermore, to compensate for the defect that the above scheme works incorrectly when the opposite busbar is faulty, a remedial reclosing strategy is proposed under different communication conditions. Finally, based on the PSCAD platform, the excellent performance of the proposed protection scheme is verified, and it can bear the protection function reliably for the 220 kV high-voltage system.