The invention discloses an extension neural network pattern recognition method based on priori knowledge. The method includes the following steps that (1) a training sample set and a knowledge base are prepared; (2) an initial weight value of an extension neural network is determined according to training samples and the priori knowledge; (3) the extension neural network can be trained by the utilization of the training samples, if a training process is converged or the total error rate reaches a preset value, training is stopped, and a weight value vector, after the training, of the extension neural network is kept, and otherwise the training is continued; (4) the trained extension neural network is used for performing pattern recognition until recognition of all objects to be recognized is completed. According to the extension neural network pattern recognition method, under the common driving of the priori knowledge and the training samples, learning of the extension neural network is guided, training and learning of the extension neural network are completed, the learning burden of the extension neural network is relieved, the performance of the extension neural network is effectively improved, training time is shortened, and recognition accuracy is improved.