Abstract: Based on Reiter’s theory for multi-fault diagnosis from first principles，a method for solving minimum complete test set by using fault-test matrix is proposed.This method can be divided into two steps：According to the knowledge on the system structure and test vector，combined with the test-failure matrix to identify a candidate conflict set；Based on the candidate conflict set to determine the minimum hitting set group，to generate a minimum complete test set.This method can effectively solve the minimal complete test set，and speedup the process of fault diagnosis，with greatly reducing the workload to impose redundancy test vectors.

Key words: fault diagnosis, test set minimization, conflict identification

摘要： 应用第一原理的故障诊断思想，基于故障测试矩阵，提出了一种根据系统每一个故障都可检测的行为与系统所有故障不能检测的行为之间的不相容推理技术，来判断和求取系统存在的所有最小完全测试集的方法。方法分两步：一是根据系统的结构和测试矢量等知识，结合故障测试矩阵，识别冲突集候选；二是根据冲突集候选，确定最小命中集合组，生成最小完全测试集。该方法可有效求解最小完全测试集，减少测试矢量施加的工作量，提高故障诊断的效率。

关键词: 故障诊断, 测试集极小化, 冲突识别