Fault localization is a time-consuming and labor-intensive job in the process of software debugging. Debugging automation has important significance for replacing the manual check and improving the efficiency of software debugging. Specifically, many researchers have focused on fault automation location based on program spectrum in recent years. Aiming at the single error phenomenon, this paper presents a new fault localization method based on improved program spectrum. The method is based on the fact that the test case operation must cover the fault statement if the test case runs erroneously under the single error condition. It checks the coverage statements for all fault test cases, and then obtains the fault base. The fault base is used to improve the fault localization method of software debugging. Finally, the Siemens test suite is used as the test data to compare the effect of different methods on fault location and efficiency. The results show that the proposed method can greatly improve the effectiveness and efficiency of fault localization.