In order to obtain the droplet diameter and spatial distribution and velocity of gas-liquid flow, interferometric laser imaging droplet sizing technique (ILIDS) is studied. ILIDS is a novel planar measurement technique for droplet size and velocity vector for spray measurement that has high precision for droplet sizing and localizing. An automatic analysis method, which bases on image convolution localizing, Fourier transform and concise cross correlation algorithm, is developed for obtaining droplets' diameters and velocity of spray by using PIV setup. The method is experimentally tested on the water spray generated by an injector, and the different region of the spray is measured. The velocity field obtained by the method is calibrated by the normal particle image velocimetry (PIV) method, the result shows that the difference between velocity vector by two methods is only 0.38%.