The present invention discloses a 3D portrait food printing method. The method comprises the following steps: a human face image is input, the input human face image is convert to a gray scale map, 83 human face feature points are found, preprocessing is conducted, gray values of the human face feature points are strengthened, an ETF algorithm is used to construct a smoothing direction field of the human face image, a FDOG algorithm is used to conduct anisotropic Gaussian filter based on a direction field flow direction, binarization is used to obtain human face image contours, an 8-connected depth-first traversa is used to get rid of local details to obtain simplified human face contour image, a prim algorithm is used to connect two closest line segments to form an one-stroke human face contour path, an erosion algorithm is used to simplify the path to finally obtain a human face 3D printing path. The 3D portrait food printing method simplifies the portrait 3D printing generation path, at the same time retains most contour information on human face, is also clear, friendly in interface is, and great in results, and can be used for the 3D food printing, commercial apps and other fields.