Event Viewer in the administrative tool found that 1433 was occupied. Reference: 1, windows platform is executed under the Windows command line window: C: \ > Netstat-aon | Findstr "80" TCP127.0.0.1:800.0.0: 0 Listening 2448. Seeing that the port is occupied by the process with the process number of 2448, continue to execute the following command: c: \ > Tasklist | Findstr "2448" thread.exe 2016consconsole 01064k finally found that Firefox occupied tcp 1433, so just close Firefox and start sqlserver. Depressed, there is such a thing!