Preliminary results for the generation and application of the high power ion beam(HPIB) on the FLASH Ⅱ accelerator are reported. The structure and principle of the pinch reflex ion beam diode are introduced. The equation of parapotential flow is corrected for the reduction of diode A-K gap due to the motion of cathode and anode plasma. The HPIB peak current of ～160kA is obtained with a peak energy of ～500keV. Experimental investigations of generating 6—7MeV quasi-monoenergetic pulsed γ-rays with high power ion(proton) beams striking 19F target are presented. In addition, the results of the thermal-mechanical effects on the material irradiated with HPIB, which are applied to the simulation of 1keV black body radiation x-rays, are also discussed.