In the process of using molecular beam epitaxy (MBE) technology to grow GaSb thin film materials, we use a reflection high-energy electron diffractometer (RHEED) to realize real-time monitoring of GaSb thin film preparation. We obtain the relationship between the growth parameters and the diffraction pattern change and determine the the temperature of deoxidation layer by analyzing and studying the deoxidation layer on substrate and its growth process based on the RHEED diffraction oscillation pattern. By calculating the growth rate, the optimization of source temperature, beam-to-current ratio, and growth temperature are optimized. Preliminary characterization and analysis of the surface quality of GaSb epitaxial film using double crystal X-ray diffraction (XRD) technology show that GaSb epitaxial film can meet the device preparation requirements and provide experimental basis for the next step of preparing quantum wells and superlattice structures by molecular beam epitaxy.