This paper is devoted to guiding parents in organizing classrooms and bedrooms for their children, ensuring that they have the most reasonable position to rest and study. That is how to design, arrange, and select items in a room to serve two children of the same sex, aged from 6 to 18. Arrange the bed to suit the cramped housing situation. Install study tables and chairs so that children can sit and study comfortably. Choose to buy a bookshelf and hang it on the wall so that it is steady and within reach of your children's operation and use. Essential daily items are arranged neatly so that children can conveniently take them out, use them, and store them in the right place. Thanks to having an ideal room to rest, study, and conveniently use equipment, children will develop well in literature, physical skills, and aesthetics and will always love their family. Later, when the children grow up, no matter where they go, the image of the beautiful little room of their childhood will always be kept in their memories. The interior design of the classroom and bedroom for two small children in a family is fully and clearly shown in 3D images by us. We have presented how to arrange and install items in the room so that everyone can apply this design to their family situation.