1. First prepare a piece of A4 paper, fold the A4 paper in half once, and then fold it in half again, as in the picture.

2. Open the folded small quadrilateral paper, similar to a triangle, with the tip facing you. Pay attention to aligning the two creases as shown in the picture.

3. Turn over the folded paper and unfold the rectangle on the left side, similar to a triangle.

4. Fold the upper right layer to the left and the bottom layer on the left to the right.

5. The left and right edges of the upper layer are centered and coincide with the center line.

6. Turn it over and the side lines converge with the center line.

7. Fold the edge of the center back so that the two lines overlap.

8. Fold the top layer down along the crease on the top.

9. Continue to turn over and turn down the upper layer.

10. Insert the four small triangles turned down into the four large triangles below and compact them.

11. Stand up the corner that has been facing you.

12. Finally open it and the paper folding box is ready.