I want to make a sword that does no knock back

I am making a kit in Minecraft and I want to get a sword with no knockback.

Is there a way to make that sword?

Items will always do knockback because all mobs have the ability to take knockback. If you uses any item (even your fists) and hit a mob they will take knockback. Therefore like Snafu_ said, it will be impossible to accomplish such a task with any item (not only a sword) unless you modify the mob taking the knockback (like adding a knockback resistance attribute).

The only way you'll be able to achieve this effect is by giving the other players/mobs the knockback resistance attribute modifier.