Optimization of failure protection plays a key role in maintaining the power system reliability. The effect of current transformer tailing on breaker failure protection is analyzed in detail. In addition, a novel method of current transformer second current feature identification is proposed based on recursive least square algorithm. Then, a new breaker failure protection with determination coefficient is presented. At last, the effect of fitting results and current type on the new scheme is analyzed. The novel scheme not only shortens the breaker failure protection setting time, but also ensures its malfunction. The simulation proves that the new logic is correct. This work is supported by State Grid Guide Project of Research on New Protection Control Design Technology for AC Side in VSC-HVDC Environment (No. B3441518K002).