For extracting the blood flow signal of the human skin blood capillary, a combination method of speckle variance (SV) based on the swept source optical coherence tomography, and Doppler algorithm is proposed. This method takes advantage of SV algorithm to get the blood flow signal intensity and advantage of Doppler algorithm to obtain phase. SV algorithm calculates the variance of intensity at the same location of two frames. Doppler algorithm calculates the phase shift between adjacent A scans in order to obtain frequency shift. However, the phase of the swept source output and the sampled signal drift slowly over time, causing the delay between the trigger signal and the subsequent analog to digital conversion to vary within a sample clock cycle. To correct the change in phase, double reference mirrors are used in the experimental system. We adjust the phase shift between adjacent A scans of the two reference mirrors to correct the phase of the corresponding blood flow. Sample simulation experiment and human skin imaging experiment are carried out. SV algorithm is used to obtain the intensity of blood and Doppler phase shift after correction is used to obtain the direction of blood. Blood flow intensity with direction information is obtained by combination of the two methods.