Reversible data hiding in encrypted images (RDH-EI) is important in secure cloud computing and privacy protection. In order to improve the embedding rate, the characteristics of high pixel depth and high pixel distribution continuity of medical DICOM image was considered, and a reversible data hiding method in encrypted images combining two compression strategies was proposed in this paper. Firstly, the sender preprocessed the image and embedded the mark according to the number of consecutive high-order bits in the pixel. Then a unique block encryption algorithm was used for encryption, which ensured the plaintext information was not leaked while some image correlations were retained. The data-hider embedded additional information in the corresponding position according to the mark. In addition, in order to further improve the embedding rate, the data-hider can also make difference in the block and compress the space for information embedding. Experiments show that the method not only has high information embedding rate, but also has good security performance.