In a crystallizer of a wide side wall and a narrow side wall chilling and pouring the steel belt continuously, the wide side wall forms an infusion area of a pouring pipe and extends upwards, and the side edge of the infusion area has a parallel end. in order to reduce the loading of a condensation shell of a casting blank, and to reduce the abrasion of the crystallizer and the needed traction, and to improve the distributing state of the steel water, the crystallizer has a rectangular transition surface (12) which transits to the lower section of a certain shape in wide side walls (1 and 2) as a changing angle descended gradually towards the side along a horizontal line (C-D). |