以最小模式启动sql
cd   C:\Program Files\Microsoft sql Server\MSsql12.MSsqlSERVER\MSsql\Binn运行
sqlservr.exe -f -sMSsqlSERVER
马上修改内存设置，重启后服务正常。
EXEC sp_configure ‘show advanced options‘,‘1‘ RECONFIGURE WITH OVERRIDE;
EXEC sp_configure ‘max server memory‘,400000 RECONFIGURE WITH OVERRIDE;
EXEC sp_configure ‘show advanced options‘,‘0‘ RECONFIGURE WITH OVERRIDE;