An accumulation model of X-ray and debris in a high altitude nuclear explosion is built in this work. Using the established model, we simulate the energy accumulations of four large scale experiments (i.e. the Checkmate, Starfish, K3 and K4) conducted by the United States and the Soviet Union. The dynamics of the kinetic accumulation at 100–200 km altitude is analyzed. Our simulation results show that the kinetic patch spreads a relatively small spatial region and has a large energy density compared with the X-ray patch. The accumulation of the debris ions can be finished within around 0.5 s, and two absorption peaks (hence two kinetic patches) can be observed at an altitude of about 115 km and the burst point. The shape of the kinetic region projected onto the horizontal plane is roughly elliptical, the eccentricity will be smaller at higher latitudes, and the area will be larger at higher altitudes. Away from the bursting point, the maximum energy density of the kinetic patch is near the magnetic field line that crosses the bursting point. Within the magnetic bubble, the maximum energy density of the kinetic patch occurs near the bursting point.