I encountered with this insect on the wet floor in Sri Lanka. Is it dangerous?
Actually, the antennae of that insect are not scary at all!
In your image, the antennae are pointing down; those forceps-like structures pointing up are part of abdomen, and are called cerci.
That insect (probably a male) is an earwig, from the Order Dermaptera. In the image below, the antennae are at the left, while the abdomen and the cerci are at the right:
Narrowing down the the Genus of your specimen is more complicated, but here is a list of earwigs from Sri Lanka: https://en.wikipedia.org/wiki/List_of_Dermapterans_of_Sri_Lanka
Regarding the danger: earwigs are not dangerous. The cerci may be scary, but they normally are not capable of hurting a human. Also (and I hope you don't believe urban legends), they do not lay eggs in human ears: http://www.snopes.com/horrors/insects/bugear.asp