本文在对实例相似性进行深入研究之后，提出了实例特征的概念和基于实例特征的实例相似性判断的两个论点．在这两个论点基础上提出了面向设计任务的基于神经网络的实例检索模型和面向实例特征属性的基于重构分类网的实例检索模型 After in-depth study on the similarity of instances, this paper presents two conceptions of the concept of instance features and the judgment of instance similarity based on instance features. Based on these two arguments, a case retrieval model based on neural network for design task and an instance retrieval model based on reconstructed classification network