Hello Phew! Perhaps a better way of saying it is this: "Children's' innocent view on life." / "Children's' innocent view on the world." or "Children's' untainted view on life." or "Children's' untainted view on the world." The word "untainted" means "unspoiled" or "not ruined". I hope that helps!

1) Their gaze is pure/innocent. This option is the better one and appropriate for your purpose. 2) their unspoiled/unstained gaze This option is less appropriate for your purpose. "Unspoiled" is more used to describe is something that has expired (usually in reference to food, but can be used in other cases, too).

Thank you all. :)

Gaze is really a physical thing that should be different from the child's outlook, which is more a worldview, something mental. That said, 1 is fine and I would never question it. Don't say unstained. To make it more natural: They gazed/looked innocently.

in my submission The heart of the children is absolutely innocent When they have problems that they don't understand， They're bound to look confused This is the way he looks at you That's the innocent cow dung of the children