Ghost imaging (GI) is a technology of nonlocal optical imaging, which is widely used in the field of information encryption. However, there are some inherent shortcomings in the encryption process, such as imperfect security and low imaging precision. To solve these problems, we propose a camouflaged encryption mechanism based on sparse decomposition of principal component orthogonal basis and ghost imaging (CSP-GI). Unlike the traditional encryption method, there are two-level keys and ciphertexts. The information of the secret image is hidden in the camouflaged image to improve the security of the system. The use of the sparse decomposition of principal component orthogonal basis expands the information content of encrypted transmission, improves the accuracy of reconstructed image, and reduces the reconstruction time. The simulation and experimental results show that the proposed method not only has good security and robustness but also reduces reconstruction time.