A method for building a cloud-based medical image database for the protection of patient information. A method for building a cloud-based medical image database and reading a medical image therefrom includes a acquiring a medical image of a patient by a medical device; separating patient information data from medical information data in the medical image; encrypting the patient information data using a block chain technique; separately transmitting the encrypted patient information data and the medical information data to a cloud database and storing the same in the cloud database; decrypting the encrypted patient information data stored in the cloud database, using the block chain technique; and reading the medical image to perform diagnosis and consulting for the patient.