The utility model provides a square iron structure of a die. The square iron structure comprises square iron and needle plates, wherein the square iron comprises upper square iron and a lower square iron; the needle plates comprise an upper needle plate and a lower needle plate; the upper needle plate and the lower needle plate are transversely arranged in parallel; the upper square iron is mounted at the upper end of the upper needle plate and the upper end of the lower needle plate; and the low square iron is mounted at the lower end of the upper needle plate and the lower end of the lower needle plate. Through the up-and-down arrangement of the square iron, the upper needle plate and the lower needle plate are fully exposed, so that the moving directions of the needle plates can be clearly observed to avoid the ejection or oblique ejection of an ejector pin, which is favorable to improve the qualification rate of a processed product.