The parameters measurement of liquid film in gas-liquid two-phase an nular flow is of great significance for the study of heat and mass transfer and flow characteristics.Laser-induced fluorescence technique based on optical measurement principles to measure film parameters can be simply implemented with high accura cy and without interference of flow fields. Compared with the traditional measurement methods,the method combining the laser-induced fluorescence technique with the cross-correlation technique is developed to measure the liquid film velocity and analyze the flow characteristics.With the aid of digital image processing t echnology,curves of film thickness at different locations are figured out based on the film images shot by high-speed camera. The flow velocity of the liquid film is accurately measured by processing the images at a fixed interval frame based on the cross-correlation technique.The parabolic fitting technique can be used to estimate the largest correlation coefficient wi th a higher accuracy and improve the measurement accuracy of film velocity.The experimental results show that the non-intrusive measurem ent method with a wider range of application can effectively detect the liquid film "break-up" phenomenon and extract the li quid film flow velocity with a higher accuracy.