I noticed when people get the search result from google, it automatically shows the sub links under the main site link:
is that possible if I want to modify the sub menus with my own site as a result in google? Which means when people search for my website, the sub menu of my website is the one that I created?
Google chooses when Sitelinks are shown for a website. You have no control over when that happens. It usually only happens when a website is very popular and a very obvious choice for a very popular search term.
If your site does qualify your site links you can suggest pages you do not want to appear in Sitelinks in Google Webmaster Tools. But this only is a suggestion and is only available after Sitelinks is available for your site.
Apparently, Google has removed the option to suggest pages for exclusion from sitelinks (mentioned by John Conde in his answer).
来源：https://stackoverflow.com/questions/8745233/sub-sitelinks-in-google-search-result