I find a post of IMDB programmer of iOS9 version:
"We have an update coming very soon with iOS 9 support, including Spotlight support and deep linking. It's just waiting on Apple approval at this point.
Spotlight indexing works mainly by Apple's spiders indexing our website and anonymously tracking usage of pages in our app. It's not possible for the app itself to insert millions of movies into an index on your phone, so it could take days or weeks before Spotlight search gives you the best results. In the initial version, we will at least index the movies and cinemas playing near you.
At launch, at least Bing/Google results in Spotlight will deep link directly into the IMDb app, even if you have to scroll down to see those results."
Now it's all clear!