In order to realize the portability of laser speckle blood flow imaging equipment, the mobile phone speckle contrast blood flow imaging technology is studied. By analyzing and reorganizing the light intensity signal of the color filter array, the problem that the color image sensor can not obtain the speckle signal is solved. A speckle contrast analysis method based on mobile camera is proposed. The low-frequency region of the image is enhanced by two-dimensional discrete wavelet transform, and the background region and foreground blood flow region are segmented and denoised by K-means clustering and Ostu algorithm. Finally, in order to verify the segmentation results of the two algorithms in different cases, blood flow simulation experiments and microcirculation blood perfusion experiments are carried out respectively. The results show that Ostu algorithm has better segmentation and denoising performance under different blood flow models, solves the problem of blood flow image distortion caused by mobile phone's own algorithm, and improves the visualization effect of the image.