With the development of the times, the mailbox was gradually replaced. "In the past, the carriage and horse were very slow, the letters were very far away, and only enough to love one person in one's life." This sentence from Mu Xin's "Once Upon a Time Slow" must be familiar to many people. Every time I see a green mailbox and a green box door on the side of the road, I often look at it a few more times, because in the era when the Internet was not popular, there were too many people's "expectations" hidden there ". For this reason, a pencil sharpener with the prototype of the mailbox is designed. The traditional shape of the mailbox and the pencil sharpener are fused and the shape of the pencil sharpener is like a continuous envelope, giving people good memories. The mailbox may disappear in the near future, but the pencil is one of the necessary tools for everyone's student days. This means that with the existence of pencils, the mailbox will not "disappear" in people's world. Continue to pass on the image and meaning of the mailbox in another way, cultivate children's nostalgia, and let children experience different fun in the boring process of sharpening pencils.