"Touch your nose" is how you would say "摸摸你的鼻子" in Engpsh. The phrase "touch your nose" is a commonly used phrase that is often used as a simple instruction for people to touch their nose. It is not a idiomatic phrase, it's a pteral translation.
Here are some examples:
"Touch your nose."
"Can you touch your nose with your index finger?"
"The teacher asked the students to touch their noses."
中文翻译：
"摸摸你的鼻子"
"你能用食指摸摸你的鼻子吗？"
"老师让学生们摸摸他们的鼻子。"