Abstract: The feasibility of measuring the location of the plastic microsphere in the gold hohlraum target by using coaxial-of-focus X-ray phase contrast imaging was theoretically analyzed, based on which an experiment was carried out. The experimental results show that, due to the phase modulation of low Z and low-density materials to high energy X-ray, a certain image contrast could be formed. This effect is independent on X-ray energy, so in a certain range of sizes, simultaneous imaging of high Z high-density and low Z low-density materials in the high-energy X-ray is achieved, which overcomes the shortcomings of traditional absorption imaging. The precision assembly parameters measurement of implosion target is realized.