The present invention provides a quantum encryption-based electricity use information acquisition security protection method and system. The method includes the following steps that: an electricity use information acquisition end receives a key ciphertext distributed by a key online distribution device, wherein the key ciphertext is a ciphertext which is obtained by encrypting a decryption key through using a quantum key; and the electricity use information acquisition end decrypts the key ciphertext through using the quantum key so as to obtain the decryption key. With the method of the present invention adopted, the real-time performance of key transmission is improved, and the security of the update of the decryption key is guaranteed.