This question already has an answer here:

When doing a one and a half step bend on guitar, or even a whole step, I can't seem to keep my finger from grabbing the other strings and I can hear them. Do I need to set my action differently? I've got them where they should be according to the Jackson specs.

marked as duplicate by cyco130, Dom, Meaningful Username, Dave, Matthew Read Apr 30 '15 at 15:22

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.