Why Bing suddenly dropped index of website? My website indexed in Bing, after some days it dropped index of my website, i dont why? please suggest some idea to re-index it in bing.

There maybe some faults and some mistakes which do not comply with webmaster guidelines. You need to audit your website and check the errors in webmaster tool to resolve it.

There might be some changes going on in bing. You can wait or just try to re-index it as you did before