Applying 3D reconstruction technology to the field of medical plastic surgery is an effective means of assisting medicine to provide doctors with preoperative preparation data for reference. The current 3D scanners have high cost, short lifespan, large structure and difficult maintenance, which are not conducive to the popularization of this technology in the field of medical plastic surgery. A 3D imaging method of local human body features based on smartphone photogrammetry is proposed. The speckle pattern is projected onto the surface of the object to be measured by combining the micro projector. The modulated speckle pattern collected by the smartphone is combined with the prepared speckle template pattern. Between them, the local grayscale correlation of the image is used for matching to realize the reconstruction of the 3D model, and the complete 3D model is restored through the multi-view point cloud stitching technology. The efficiency and convenience of reconstruction are improved, and the utility model has the characteristics of low cost and simple operation. Taking the local features of the mannequin as the surface to be reconstructed, the 3D reconstruction of the continuous surface with weak texture is realized. The experimental results show that the average error of 3D surface reconstruction with this method is 0.43mm and the standard deviation is 0.30mm, which can meet the needs of actual measurement.