In this paper, the data extracting method of high speed particle field ejected from material surface under explosion using in-line Fraunhofer holography was introduced. During the reconstruction,the image of the 3D particle field reconstructed from hologram was divided into many small slices and then these slices was acquired by a CCD camera. During the data processing, first of all whether in the whole or in some parts of the image extracting larger particles using edge detection based on the edge of particles in the image was determined, then the image was divided into several small areas and these small areas was segmented using a threshold. On the last process of correcting the result, the particles that was larger or smaller than a standard was confirmed as noise and that was repeatedly disposed were got rid of. Using this method, the space-distributing and the statistic of the particles were achieved.