Based on the high energy γ-ray yield from the H-bomb D-T fusion reaction, it brings forward the idea applying the 16.76 MeV γ-ray to judge whether the H-bomb happens or not, and to deduce the explosion TNT equivalent accurately. The Monte Carlo N-Particle was applied to simulate the high energy γ-ray radiation characteristics reaching the geosynchronous orbit satellite, and the CVD diamond detector suit for the requirements was researched. A series of experiments were carried out to testify the capabilities of the diamond detector. It provides a brand-new approach to satellite-based nuclear explosion detection.