If you’re talking about constantly dripping water, there’s no evidence that the technique of Chinese water torture was ever really used except in B-grade spy movies.
However, other water tortures were used in China.
With the real Chinese water torture, the victim had his hands tied behind his back and his head submerged in water for various lengths of time.
Some variations were used: A torturer could alternate dipping the victim’s head in scalding-hot and then ice-cold water until the victim either spills the beans or dies.
Yet another variation is to place a water-soaked cloth over the victim’s face, lay him on his back, and pour water over his face until he drowns, or comes close to it, anyway.
The truth, however, is that these methods are no more strictly Chinese than spaghetti is. Just about every culture that’s employed torture through the ages has used these methods or ones very similar.
Maybe the Chinese invented these methods first, as they have so many other things, but probably not.