Is it possible to have two web application projects (one main website and one running in a virtual directory such as an admin site) share the same application pool to allow the sharing of content in the back end such as static lists, session state etc?
A quick google search turned up this related question IIS App Pools & Static Classes with the answer that the two web sites will still be in different AppDomains and will not share Static instances.
If you need to share data between your web applications you would be better served by setting up a shared database/service for the two web sites to communicate via. This would also better adhere to best practices.
来源：https://stackoverflow.com/questions/12786573/two-websites-with-single-application-pool-to-share-resources