To consider the effect of low-cutoff energy of non-thermal electrons, it is necessary to calculate with more strict theory of gyro-synchrotron radiation.

We drew the conclusion that the frequency distribution of the non-thermal radiation from a general spherically-symmetric and charged evaporating black hole depended on the time.

It can be find that average photon number of thermal radiation field and multi-photon transition process have intense influence on the non-classical properties.