Abstract: The present application provides a universal quantum secure device and methods of sending and receiving data. A quantum encryption and decryption module can realize quantum encryption and decryption of data requiring quantum encryption service, thereby ensuring that data sent and received by the universal quantum secure device from a conventional network are transmitted in ciphertext form. An isolation module can realize isolation between the communication module and each of the quantum encryption and decryption module and a privacy module, so that security of the privacy module and security of the quantum encryption and decryption module are protected from being affected by data received by the communication module from external network. Since the privacy module does not communicate with external network, and encryption and decryption of the data can only be carried out in the quantum encryption and decryption module of the universal quantum secure device, improving data security.