In fast ignition mode by exploding push, the fuel is first compressed by a conventional inertial confinement fusion driver, producing a low density hotspot surrounded by a relatively cold and dense main fuel region, and then a short (about 10 ps) pulse, high-power laser is injected, the suprathermal electrons heat the cold region, and the cold shell explodes, compressing and heating the hot-spot. The analysis in this paper shows that the compressing rate of hot-spot is 64, neutron yield is about two orders of magnitude greater than before, and the energy gain is 3 times increased. But the ion temperature is increased slightly, for the mass of cold region is too large. If the mass of cold region is decreased or the energy of relativistic electrons is increased above 10 kJ, the rise of ion t