In order to quickly obtain accurate 3D model of wound cavity, Firstly, the orthogonal images synchronous photographed by x-ray were preprocessed by format conversion, contrast adjustment and denoise. Secondly, the edge contour can be extracted through level set method, and ellipse can be used to approximate the cavity cross-section. At last, the three-dimensional reconstruction was completed through the powerful data visualization of Matlab. The results show that this method gives visual and effective 3D model of wound cavity and provides a theoretical basis for ammunition design and wound treatment.