An output method and an output device include steps below. A first electronic device sends a file to a server and generates a piece of verification information corresponding to the file. A second electronic device receives the piece of verification information. An output device reads the piece of verification information, and obtains the file from the server according to the piece of verification information. The output device receives a first verification code via a user interface, determines whether the first verification code matches the piece of verification information, and outputs the paper document of the file when the first verification code matches the piece of verification information. The output device sends a second verification code, generated according to encode data of the file, to the second electronic device for a further verification and deletes the file after the output device output the paper document of the file.