High-standard stone is actually high-standard stone particle size, gradation, crushing value, silt content, firmness and so on. For example, the crushing value of gravel 1-2 is less than 10, the silt content is less than 1%, the needle shape is less than 8, the gradation is 5- 16, the grain shape is full, the pebble is less than or equal to C35, the crushing index is less than or equal to 16, and the crushing index is greater than or equal to C35.