Abstract: The paper carries out geometrical parameter measurement method research of the metal lattice material. The CT (computed tomography) image of a connection rod of high energy selective laser molten lattice structure is presented as an ellipse. According to the image characteristics, the paper fulfills automatic recognition of the position parameter, shape parameter for the single ellipse and automatic measurement of geometrical parameter for the metal lattice material structure, based on the longest distance between any two point on the ellipse being long axis. The testing result basically complies design value. It provides a reference for image automatic recognition of other part digital radiography and industrial CT.