Abstract: High-speed magnifying photography is an economical non-intrusive measurement method. It can be used to measure the droplet size in flight. This paper describes the measurement theory, experimental devices and the measurement results of this technique used for the determination of droplets atomized by an industrial burner. For this test, the sauter Mean diameters measured by the industrial burner are 58 micron at 400mm section and 62 micron at 500mm section respectively. The test results are satisfactory with relative error less than 8%.The mi-nimun measurable droplet size is 12μ