This paper proposes a new method of diagnosing 16.7 MeV high-energy pulsed gamma, named "scattering-absorbing method" . The ratio of the sensitivity of HEG to that of the LEG can reach 10⁶ to 10⁸ by this new method. The sensitivity of 16.7 MeV high-energy gamma ranges from 10^-21 to 10^-16 C·cm². It's better than the traditional method which bases on the magnetic analyzer and Cherenkov detector on some aspects.