The invention discloses a method for controlling on-line prediction of continuous casting blank quality, which belongs to the field of metallurgical automation control. In the method, a comprehensive quality prediction rule based on an expert system, mathematical statistics and a neural network is programmed by secondary control software, and data communication is performed by the secondary control software and a primary basic automatic control system, so that the automatic prediction of casting blank quality in the continuous casting production process is realized; and a quality judgment system overall framework comprises an influence factor real-time data acquisition module, a casting state and casting information tracking module, an abnormal event and casting blank quality prediction module, an off-line simulation system, a quality prediction system database, a primary communication interface module and a system human-machine interface (HMI) picture. The method has the advantage that the on-line automatic prediction of the casting blank quality in the continuous casting production process is realized.