Optical imaging is one of the most important techniques for information acquisition. As a novel technique based on high-order correlation of light field, ghost imaging can reconstruct the two-dimension image of objects by using only a single pixel detector. It has the advantages of object-image separation, high imaging sensitivity and strong robustness, which promises new opportunities and prospects for the development of optical imaging. However, the imaging mode based on multi-frame cumulation takes toomuch time to acquire images, which severely limits the efficiency of image acquisition. In order to solve this problem, research on efficient reconstruction algorithm is one of the most practical methods to improve the imaging quality and imaging efficiency besides the optimization designs of system structure, light source and detection. A good reconstruction algorithm can not only greatly reduce the number of measurements required for imaging, improve the efficiency of information extraction and quality of reconstructed image, but also reduce the requirements of hardware. In recent years, many different kinds of reconstruction algorithms have been developed. In this paper, the principle and mechanism of ghost imaging are briefly reviewed, and then the basic principles of several typical algorithms of ghost imaging are introduced systematically, as well as their advantages, disadvantages and applicable scenarios.