Combined with the characteristic of wavelet entropy， the theory of wavelet entropy is presented in the non-unit transient protection and accelerated trip of transmission line protection. A new scheme of two applications of protection based on the concept of wavelet singular entropy is presented. The PSCAD/EMTDC simulation results show that the scheme of non-unit transient protection is insensitive to fault type， fault location， fault resistance and fault inception angle. The protection arithmetic is with favorable adaptability and sensitiveness. Compared with the criterion of wavelet model maximum， the criterion of accelerated trip overcame the influence of signal magnitude. The technique of wavelet entropy shows good prospects in the field of power system protection.