Management system and management method for access authorization of electronic document

A management system and a management method for access authorization of an electronic document are provided. The method includes: storing, by a cloud server, a hash value of a first redacted document, a ciphertext of confidential information, an authorization level corresponding to the confidential information, and an index corresponding to the confidential information, the first redacted document includes a redacted area corresponding to the index; storing, by a first terminal device, the first redacted document, and receiving, from the cloud server, the hash value, the ciphertext, the authorization level, and the index; recovering, by the first terminal device, the redacted area of the first redacted document according to the index, the authorization level, and the ciphertext so as to generate a second redacted document in response to the hash value matching the first redacted document; and transmitting, by the first terminal device, the second redacted document to the cloud server.