A three-dimensional real-time observation instrument was developed, which was consisted of crystal part, optic observation part, and result analysis part. The crystal growth and flow movement was observed by the two-eye observation method. A now growth furnace and crucible, being suitable for Bridgman method crystal growth, was developed. The solidliquid interface of NaNO3 was visualized. At last the image visualized was synthesized into three-dimensional image by a processing software.