The invention discloses a spherical high-pressure reaction kettle for hydrothermal crystal growth. The spherical high-pressure reaction kettle comprises a kettle body, wherein the kettle body is a solid sphere; a chamber is longitudinally formed from the kettle body surface to the kettle body inside on the kettle body to form a kettle cavity of the kettle body; and a dissolution area and a crystallization area exist in the kettle cavity. By adopting the high-pressure reaction kettle to perform hydrothermal artificial crystal growth, a stable temperature field with double temperature areas can be realized, solution convection in the kettle cavity is slowed down, seed crystal corrosion is avoided, and fast and stable growth of crystal is promoted.