If you don't die, you won't die
is an online buzzword. The whole sentence is "If you don't die, you won't die. Why don't you understand!" , which means to go looking for trouble and get unlucky, is widely popular in major communities, forums and even mainstream media.
explanation:
To die is to seek death, which often refers to the act of seeking one's own death.
if you don't die, you won't die, which means: if you don't die, you won't die. It often means "asking for trouble" and "biting off more than one can chew".