1. Prepare a square piece of paper, and then face it diagonally so that the four corners are aligned.

2. After folding the square paper in half, fold the center of the long edge in half, and align the four corners after folding.

3. Open the folded corner for the second time, then fold two corners up along the middle crease, and align with the edge after folding.

4. Open the two corners folded upward from the middle, and then fold the lower corner upward and flatten it, so that the edge is aligned with the hypotenuse.

5. Turn the folded paper over, and fold the two small hypotenuses below to the top, so that the folded edges are perpendicular to the bottom.

6. Fold both sides of the hem upward along the outermost two creases, and the hems are aligned with each other.

7. Fold a long corner up along the overlapping edge, and then fold the upper corner into the overlapping edge.

8. Fold the long corner on the other side according to the above method, so that the two sides are symmetrical after folding.

9. After the shape of the ingot is folded, open both sides of the bottom of the ingot. Then flatten the middle edge, arrange the corner ingot and fold it.