TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: In the step (e), the pressure of the solubility equilibrium supercritical solution is adjusted to be in 10.2-40.8 MPa, and the temperature of the solubility equilibrium supercritical solution is adjusted to be 32-38 degrees C. In the step (e), the heating base is heated up to 35-80 degrees C. In the step (e), the coating substance is deposited on the substrate for 5-30 minutes. The supercritical vapor deposition method further involves a step (f) of relieving the pressure of the solubility equilibrium supercritical solution, thereby generating a gas-liquid mixture. In the step (f), the pressure of the solubility equilibrium supercritical solution is relieved at a rate of 5-30 ml/s at normal temperature and pressure. The step (f) further involves sub-step of heat-treating the substrate, so that the film on the substrate is smooth and flat. The step (f) further involves sub-steps of separating the gas from the gas-liquid mixture and reusing the gas. Preferred Components: The fluid is carbon dioxide, and the supercritical solvent is a supercritical carbon dioxide solvent. The coating substance includes an inorganic compound, an organic polymeric compound or an organic metallic chelating compound. The organic metallic chelating compound includes tris-(8-hydroxyquinoline) aluminum. The substrate is an indium tin oxide glass. The film has a thickness of 10-100 nm, and the film has a roughness less than 0.5 nm. Preferred System: The film-forming unit further includes an external heater (133), which is in communication with the heating base for heating the heating base. The supercritical vapor deposition system further comprises a pressure-relieving unit (14) in communication with the film-forming unit, where the pressure-relieving unit includes an on-off valve for relieving the pressure of the solubility equilibrium supercritical solution and splitting the solubility equilibrium supercritical solution into a gas-liquid mixture. The pressure-relieving unit further comprises: a pressure-relieving separation tank (141) in communication with the film-forming unit for receiving the gas-liquid mixture and separating the gas from the gas-liquid mixture; and a recovery device (142) in communication the pressure-relieving separation tank and the pressure-enhancing unit for recycling the gas that is separated from the gas-liquid mixture to the pressure-enhancing unit. The recovery device comprises a filter and a recovery pipe. The supercritical vapor deposition system further comprises a feeding unit in communication with the film-forming unit for storing the coating substance and feeding the coating substance to the film-forming unit. EXAMPLE - No suitable example is given.