For studying the effects of technological parameters on sapphire crystal growth and quality of the sapphire,several modifications of technological parameters were made on self-developed Kyropoulos furnace during crystallization,including the adjustment of flow rate and temperature of cooling water in thermal exchanger,and the descending rate of maintain power.It was found that the cooling intensity of thermal exchanger influences the crystal growth obviously in the stage of seeding and shoulder-expanding and the influence weakens gradually,while the descending rate of maintain power during the stage of iso-diametric growth has a great effect on the crystallization rate and the quality of the sapphire.Too fast decreasing of maintain power will cause the failure of mono-crystal growth,so that the proper adjustment of cooling intensity of thermal exchanger and the careful control of maintain power during crystal growth are the two important factors for successfully producing sapphire mono-crystal.