The database requested by the login cannot be opened when SSAS deploy the data cube __ Database

SQL Server 2008 R2 created Business Intelligence project projects, and an error occurred while deploying the data cube:
OLE DB error: OLE DB or ODBC error: User ' NT authority\network SERVICE ' login failed.; 28000; Unable to open the requested database "AdventureWorksDW" for login. Login failed.; 42000.
As shown in the figure:



Later, click the Browser tab in the cube, and the error is as follows:



After a lot of tutorials, it turns out that the problem is that SSAS have insufficient permissions. However, the tutorial says:

(account) ' NT authority \ Network SERVICE ' does not have permissions to handle the cubes deployed by SSAS servers. Try on the SSAS instance and select "Security" and "NT Authority \ Network SERVICE" in the open properties.

This means that SSAS permissions are changed to ' NT Authority \ Network SERVICE, however, my SSAS permissions are this ... Then try to change the properties of the built-in account permissions to local system, resulting in successful deployment.