An epitaxial growth method of a
yttrium iron garnet film comprises the following steps: vacuumizing a vacuum cavity with a treated
yttrium iron garnet substrate to be 8.6+ / -1*10-6 Pa, and heating the
yttrium iron garnet substrate to the constant temperature which is 736 DEG C; in a heating process, feeding
ozone when heating to the temperature of 250 DEG C; after heating to the temperature of 736 DEG C, maintaining air pressure of the vacuum cavity, adjusting the
mass fraction of the
ozone to be 40%, meanwhile insulating for half a hour, and starting a reflective high-energy
electron diffraction instrument (RHEED) to adjust so as to obtain
diffraction spots of a substrate; maintaining real-time and in-situ monitoring of the RHEED in the whole process, and focusing
laser onto a YIG target through a lens by using a KrF
excimer laser of which the
wavelength is 248 nm; after growth of the film is finished, maintaining the temperature of the substrate unchanged, annealing in situ for 15 minutes, then naturally cooling the film to the temperature about 250 DEG C, stopping protective gas and cooling to the
room temperature. The obtained YIG film has uniform components, is controllable in thickness and good in process
repeatability, and has high preparation efficiency.