Abstract: Spatial distribution of spraying drop size and concentration are important parameters to investigate spraying field.Tomography measurement is shown to be an advantaged method for studying drop size and concentration distribution of nozzle atomization.Based on tomography measurement theory and fluctuation method, tomography algorithm program for reconstructing spatial distribution of spraying drop size and concentration was compiled.In order to test the program, computer simulation was used.According to tomography principle, simulation experiment was divided into two steps.First, the linear projection data of drop size and concentration were simulated with a given spraying field, and then with these simulated data, spatial distribution of drop size and concentration were reconstructed with the program compiled by the authors.The simulation result showed that reconstructed distribution field coincided with the given field.The program was used for reconstructing the spatial distribution of spraying field with experimental data obtained by the experimental platform of fluctuation method.