There are two ways to remove unused using from our code . Remove Unused Usings option in Visual Studio removes unused using in our code .

The first way is :

1) Main Menu – On the Edit menu, point to IntelliSense, point to Organize Usings, and then click Remove Unused Usings.

Remove unused usings_1
2) Context Menu – Right-click anywhere inside the code editor, point to Organize Usings, and then click Remove Unused Usings.
Remove unused usings_2
The following example shows the outcome of performing Remove Unused Usings on source code.

Before:


After: