Abstract: Three-dimensional reconstruction technology is an effective tool which can help doctors analyze and show the state of an illness and it greatly improves the accuracy of medical diagnosis.The marching cubes is a classical algorithm for three-dimensional reconstruction of medical images，but it still shows some disadvantages.Targeting to two disadvantages which are structuring surfaces by line instead of hyperbola and spending much time detecting null cubes in the traditional algorithm，this paper implements an improved MC algorithm and solves two problems by interpolating between two images and searching based on image segmentation.Comparing the traditional algorithm，experiments show that the improved MC algorithm achieves great enhancement in effect and efficiency.