In order to solve the problem of difficulty in preparation of gallium selenide (GaSe) crystals and poor chemical properties, the traditional chemical vapor deposition (CVD) preparation method for GaSe crystal is improved, and the moving heating source method for preparing GaSe crystal is adopted. A movable device for preparing GaSe crystals is built, driven by a single-chip microcomputer. The parameters such as heating temperature and moving position of the high-temperature furnace for preparing crystals are precisely controlled, and the characterization of the prepared GaSe crystal is carried out by optical microscopy (OM) and atomic force microscopy (AFM). According to this research, the monolayer smooth-faced large two-dimensional GaSe crystal is obtained by moving the heating source method. Due to the automatic precision movement of the electromechanical equipment, the high-quality large-scale production of monolayer two-dimensional GaSe crystals is realized, which is conducive to the wide application of GaSe crystals in optoelectronics and nanoelectronics.