An experimental system of digital holography for digitally recorded dynamic spray particle field is proposed. Hologram of dynamic particle field is recorded based on digital in-line holography arrangement with continuous wave (CW) laser and a high-speed charge coupled device (CCD),and the reconstructed images with different times are reconstructed numerically. The reconstructed images of a hologram of particle field are approached by adaptive filtering,and in-focus images of particle in the volume are integrated into a plane and binarized,and the edge of particle image by Roberts is extracted,then Hough transform and sub-pixel precision computing are completed,so the size and the position of particle are obtained. Digital holograms of diesel spray under different pulse widths of the injector and different measuring locations are given,and the three-dimensional (3D) distribution of particle field,and mass distribution and distribution of Sauter mean diameter (SMD) of the spray field along x-axis and y-axis are also given when pulse width of the injector is 8 ms.