The invention provides a method for solving corner cracks of casting blanks. The method comprises the following steps that 1, a temperature variation curve of corner reference temperature points and asteel cooling transformation curve in the continuous casting process are drawn in the same graph, and equipment characteristic positions are added; 2, according to the position of an intersecting point of the temperature variation curve and the steel cooling transformation curve, the starting position of embrittlement caused by formation of a crystal-boundary banded structure is determined; and 3, the position of carrying out a quenching process at the corners of the casting blanks is determined according to the starting position, determined in the second step, of the embrittlement caused byformation of the crystal-boundary banded structure is determined, and therefore the corner cracks of the casting blanks are eliminated. The invention further provides a nozzle arrangement method for solving the corner cracks of the casting blanks. According to the method, the forming position of the banded structure can be accurately found; therefore, the quenching process can be given out in a targeted manner, grain boundary embrittlement of corner austenite of micro-alloying steel slabs is changed in mechanism, and the corner cracks in the stressing process are avoided.