The invention provides a thin film deposition system and a method, and relates to the field of thin film deposition. The deposition method comprises the following steps: 1) heating metal substrate; carrying out deposition. The method is characterized in the step 1) that a current is conducted into the metal substrate at one end of the growth zone by one electrode, and out of the metal substrate at the other end of the growth zone by the other electrode, so that the metal substrate is heated by the heat emitting of the resistant of the metal substrate itself. According to the method, the quality of the prepared thin film is improved, while the preparation cost of the thin film is reduced. In addition, the consistent double-sided thin films can be easily prepared on two surfaces of the metal substrate by employing the system and method.