Abstract: A method and apparatus for continuously depositing thin film on substrate in vacuum, the method including the following steps: maintaining the degree of vacuum in the vacuum deposition chamber by disposing at least one inlet vacuum pre-evacuating chamber at the inlet of the vacuum deposition chamber and disposing at least one outlet vacuum protection chamber at the outlet of the vacuum deposition chamber; connecting each inlet vacuum pre-evacuating chamber, the vacuum deposition chamber and each outlet vacuum protection chamber by a slit; adjusting the transportation speed of the substrate to shorten the distance between two adjacent substrates before arriving at the deposition device and to enlarge the distance between two adjacent substrates after the substrate left the vacuum deposition chamber, thereby realizing the continuous film deposition process and improving significantly the efficiency of utilizing raw materials.