To query the national social science project code, you can follow the following steps:

1. Enter the list of projects supported by the National Social Science Foundation (/).

2. Select "National Social Science Fund Project" in "Project Type".

3. Enter the name or approval number of the project you want to query in Project Name or Project Approval Number.

4. Click the "query" button to query.

5. Check the required project information in the query results, including project name, person in charge, unit, project approval number and other information.

Please note that the above steps are only applicable to inquiring about projects funded by the National Social Science Fund. If you need to query other types of social science projects, you may need to use other ways and methods.